Comments: Strung this in two of my Head Speed Pros. To me it doesn't matter whether it is in the mains or crosses. If you hit the ball hard, with heavy top spin, they will break very quickly. Strings lasted me a little over two hours. Both broke within the week. Very soft feel, but expensive.
From: Carter, 5/13

Comments: This string is pretty good, but let's stop saying "gut-like." If you want "gut-like" you're going to have to pony up for the real thing. While it is very good for a multi, it does not provide anywhere near the feel that gut does. I do like it for what it is, and I may continue to use it because it is a bunch cheaper than VS, but I'll have to settle for what it can deliver.
From: Walter, 5/13

Comments: I really like this string. It has a gut-like feel and the playability of this string is so incredibly amazing. I used it for a hybrid setup with Luxilon ALU Power in the mains and Technifibre X-One Biphase in the crosses at 57/56 lbs -- works excellent in feel and durability.
From: Doodz, 4/13

Comments: This is a good string, but doesn't last at all! I got it strung at my local racquet club and the strings looked good. I took it straight to the court to try it out. I played with it for no longer than 2 hours, before I noticed the string fraying. I was very disappointed because it offers great power and spin, but the durability just isn't there.
From: Tyler, 3/13

Comments: The string does not provide power, and usually string will last me a good month, but this popped within a week. I have played with hybrids from all kinds, going from Luxilon to Gosen and everything between. It just has no feeling or power, so it becomes null. My stick is a Dunlop Aerogel 200 strung at 60lbs. I'm going to try Tecnifibre's poly, since I read good reviews of it, but if I don't like it I'll go back to Luxilon. I'm a 4.0 player.
From: Marcos, 9/12

Comments: I'm 1st singles on my high school team and for the 3 years I've been playing I've always used polyester strings to maximize my spin. After switching my racquet from the Babolat Pure Drive to the Wilson Pro Staff Six.One 90 (a significantly lower powered frame compared to the Pure Drive) for more control, I needed a more power-oriented string to balance this. After seeing many good reviews on this, I gave it a try and was very impressed. I could get the power I wanted and needed for a modern game (I'm a 4.5 player) while still getting great spin and control. Agreeing with many of the other commenters, if you are a player who hits a lot of spin and power on nearly all shots like myself, these strings will get you about 4-6 hours of play before breaking. For a 50 year old woman these might last a while, but not for 17 year old guys that like to take the fuzz off the ball. Maybe I'll try a monofilament in the mains for more durability.
From: Joe, 8/12

Comments: This is a wonderful string. I have used it for about 2 years. I am able to get about 2 to 3 months of use and I play 3 to 4 times per week. I play with two Volkl PB 10 Mid strung at 60 lbs and rotate my racquets. This would be the equivalent to lasting about 4 to 6 weeks (roughly 30-36 hours of play per racquet). However, of the 3 to 4 times per week I play, 1 to 2 times per week is with my ball machine. Playing with a ball machine is much harder on my strings than playing a match because I will hit about 120 balls in about 8 to 10 minutes. I found that the strings would fray easily and I could not afford to restring my racquets every month so I gave up on them. I quickly returned after I tried a monofilament string (I will avoid mentioning the string). I did some research and discovered that rubbing a small amount of bar wax (I use Gulf Wax) on both sides extended my string life to about 2 to 3 months. Since using this technique, I have only broken my strings twice (one after about a month of use and the other about 6 weeks of use). I would recommend warming up with used balls to knock off any excess wax before playing a match.
From: Carlos, 8/12

Comments: I did extensive research on which synthetic gut to use in my hybrid mix that would work best for me and my game. This is the one. I have used this for over 3 years now and I love it. I use Lux Rough on the mains at 56lbs and Tec Bi Phase on the crosses at 58lbs. I play at the 4.5 -open level and I am a serve and vollier and can play baseline as well. This string gives me the feel I need to play my all-around aggressive game. It does, however, only last about 4-6 sets of singles so I rotate 3 racquets. I ususlly restring when it is frayed just before breaking.
From: Dave, 7/12

Comments: One of the most comfortable strings I've ever played. Power shots, cut shots, slice shots all jumped off the strings. Unfortunately, they only did so for about 5 hours of play. Noticeable fraying after only a couple hours hitting, popped after 5-6. It's just not in my budget to be restringing once a week. It's a shame, because the strings played magnificent.
From: Jason, 5/12

Comments: I have got to say this is very good string. I have it on my K factor at 58 pounds. It has great feel, but the downside is its durability.
From: Samuel C, 3/12

Comments: The best multifilament on the market. I agree that its durability is in question but the comfort, power, and spin is unmatched! I definitely recommends this string to any tennis player at any level.
From: Ken, 3/12

Comments: I've been using this string for close to 7 years now and I wouldn't use anything else. It's combination of power and fell is unrivaled and if you are an intermediate to aggressive player, adding these strings to your frame is the easiest way to take your game to the next level. I would not recommend this product if you are someone who does not like to break stings, as the overall durability isn't the greatest. One set of strings will usually last 8 to 10 hours of heavy hitting before giving in, but in that time there is almost no noticeable loss of playability.
From: Steven, 2/12

Comments: I strung this on my wilson BLX90 in the mains with luxilon ALU power rough in the crosses. The durability of this string was better than I expected, lasting 3 months, being used 3-4 times a week and not loosing much tension. However, I did notice the feel of the string become more "dead" after about 2 months of play and the luxilon cutting into the X1 and then, just yesterday, it broke. Also there was slight fraying as I have a medium amount of top spin on my shots. But overall a nice, comfortable string. Tip: If crossing with a tough poly, try using string savers.
From: Matt, 1/12

Comments: This string has great feel and pop, and doesn't slide around. My favorite string yet.
From: Anon, 12/11

Comments: I used these strings in the mains with Signum Pro Plasma HEXtreme in the crosses. I broke two mains within one and a half hours. Otherwise, the string was nice and soft on the arm. Stringing it was nice and easy, as it was quite a flexible string. My only complaints are that I feel that it was a bit mushy and I lost the ball in the stringbed a little. Great string, but I wish that it was a bit more durable.
From: Alex, 12/11

Comments: Response to Steve, 8/11, below and others experiencing short string life, Steve mentioned the problem with the crosses wearing prematurely, I experienced the same problem. The solution is to reduce the tensions of the crosses to the mains. Not easy and you will need several trials, but if you stick with the mains at a set tension, reduce the crosses until you no longer see the wear or at least see equal wear on both. For me, it was 62 mains, 58 crosses. Every racquet head is geometrically different, so it will be trial and error for different rackets and users with different tensions.
From: Tony, 10/11

Comments: I have this string on a Prince O3 Hybrid Hornet OS, strung at 60 lbs. Stringing the racquet was a joy; one of the easiest strings I've worked with. It feels very rubbery and flexible, which I found a little surprising; this led me to think they would play a little too soft and lively. That was not the case. I found them to be a little too stiff the first time I hit with them, but the next time out they were fine; a nice crisp feel with a great combination of power, control, and spin. I hope they keep their tension because they're perfect right now. I use Gamma string savers, and find that the strings move a lot. I don't know if the string savers caused this, so next time I may not use them. Overall, I'm very happy with these strings on this racquet.
From: John, 9/11

Comments: I tried this string in a Wilson K Blade Tour after being a loyal Wilson NXT user. I prefer this string to NXT and I really liked the NXT. This string is very arm friendly like NXT but has a little more punch or feels a little more crisp. The string surface allows for some nice spin as well. I'm sold on this stuff!
From: David. 08/11

Comments: We kept X-One in the mains and put a "poly" in the crosses and that works great! The mains still look new after a week of hitting. For some reason this string is not durable in crosses.
From: Steve, 8/11

Comments: I strung it at 58 lbs full on a Head Youtek Innegra Speed Pro. Having heard such great reviews, I so much want to like the string. It hits like a dream but the dream only lasted me 2.5 hours and the center cross snapped. It could have been the topspin or the pace. I found it had better pocketing than Babolat VS but other than that, dollar for dollar VS lasts 3 weeks with 20 hours per week.
From: GS, 7/11
String type and tension: Silk 16, 57 pounds
NTRP Rating: 3.5

Comments: The X-One felt good, but the crosses shredded in a couple of days! I'm going to try these in the mains and go with a poly (Prince Beast) in the crosses hoping that will help.
From: Steve. 7/11

Comments: I'm currently using NRG2 16 in the mains @ 48 on Donnay X-Blue 99. Crosses are Genesis Black Magic 16. It's the best string combo that I have used in the Donnay's. The NRG2 plays awful close to gut. It's not as powerful as gut, but more cost-effective. It plays better with a poly in the crosses than a cheap syn.
From: JT, Nashville, TN, USA. 06/11

Comments: They have tremendous feel and comfort. I have them in a hybrid, with Luxilon Alu Power Rough in the crosses. The best bang for your buck for a multifilament that is comparable to natural gut. I'm not sure about durability yet as I've only played the strings for a little over 4 hours, but so far I'm extremely impressed and will likely buy again. Tecnifibre's premiere strings.
From: Brian. 6/11

Comments: Strung in crosses with Black Code in the mains. Played very well, but Biphase broke after six hours of play.
From: Anon. 5/11

Comments: This is one of the best multifilaments out there! I am a high school player playing with a Prince 03 Speedport Black. I had this string strung at 56lbs. After a quick break-in I was able to hit with some great spin and power. I always felt like the string had good control as well. I would recommend this to any player looking for a great multifilament string that offers great spin and power.
From: Jason, Chicago, IL, USA. 4/11

Comments: I really like this string. I use it in the mains with RPM Blast 16 in the crosses. I think it is comfortable but a bit crisper than natural gut (which I prefer) and it has almost as much power as gut. It is also durable. I think it is the best multifilament and I have tried a bunch of them.
From: Marc, Cherry hill, NJ, USA, 03/11

Comments: I LOVED my Wilson K-Gut, but for some reason, it is no longer available anywhere?!? I tried this and did not like the results. It felt as if I was playing with a pillow wrapped around my racquet...UHG! NO FEEL! I'll keep looking....
From: Jane, Wheaton, IL, USA, 02/11

Comments: My requirements in seeking out a string were that I wanted a combination of:
1. Comfort 2. Power 3. Spin 4. Control 5. Durability
I looked at sites that had reviews on 100's of strings and based on my criterion, this was the BEST choice. Other strings don't play as well, arm stiffness etc. These string are excellent and they hold tension well.
I have a mid-size and I string one at 55 and the other at 53. And there is a noticeable difference in control when I use the 55lbs (though it still has power and spin). The 53 gives a lil more pop on the serve. Regardless....I love this string!
From: Jorge, Virginia Beach, VA, USA, 01/11

Comments: I was wrong about arm friendliness of this string. It is really good. It starts stiff but then after 2 hrs of hitting it feels much much better. So I wouldn't advise lowering string tension but get used to it. Durability is also pretty good. Really a nice alternative to natural gut and it's got tons of pop. I have switched to 17-gauge version of this string, which I think one of the best multifilaments I've ever played so far (trust me I have tried many many strings). See my review in 17-gauge. Thanks!
From: Bharath, Hillsborough, NJ, USA, 01/11

Comments: how am I supposed to string these on my Youtek speed mp (100 head, 16x19 pattern) to lower frame vibrations? higher or lower tension? also, what gauge am I supposed to choose for that purpose (thinner or bigger one)?
From: Mess, Paris, France, 11/10
(Mess, please try posting this question to our Talk Tennis message boards under TW Questions/Comments or e-mail info@tennis-warehouse.com to get feedback for these types of questions--TW Staff)

Comments: Let's get serious. This is the best bang for the buck for a hybrid set-up. It pains me to reveal this info, but string it in the mains with PSG Duraflex in the crosses at the tension of your choosing. Reap the rewards.
From: Jay, Ardmore, Pa, USA, 10/10

Comments: @Matt below me. I think you should try them again because these are the best strings I have ever used. And I've used a lot of different types. AMAZING string.
From: Jorganus, Lawnmower, Mexico, 10/10

Comments: Am I missing something here? I strung these on my Head Radicals at 61. I have played USTA for almost 10 years, and before switching to these strings I used Babolat Hurricane and/or Luxilon Big Bangers. For me these strings were horrendous.. I practically had muscle all my balls for spin, very mediocre feel, and a sweet spot the size of the ball itself. For me it took 2 weeks (4 times a week) to break in. And even then, very little spin was provided, overall very disappointed with these strings.
From: Matt, Flushing, NY, USA, 09/10
(Matt, with the dense string pattern of the Radicals, I would try lowering your tension in order to gain access to more ball pocketing, which is how multifilaments are able to generate spin as opposed to a polyester, which utilizes stiffness to impart spin--TW Staff)

Comments: It's really similar to natural gut. If you like gut and want it with a lower price, this is your choice. Please use this string and save the cows. :)
From: Jack, Denver, CO, USA. 09/10

Comments: It is truly a wonderful feeling really soft string, but it is NOT good for a hybrid job with the Volkl Cyclone. I put this string in my crosses and it is already starting to fray from the stiff poly on the mains. The spin potential in this setup is not as good as the Prince Poly 3D hybrid and will not last nearly as long. However, this setup does feel wonderful in my new Babolat Aero 112.
From: Taylor, Farmington, NM, USA, 07/10

Comments: Have to say greatest string I played with. Great Durability, Great Spin and Great Comfort. However, I do not recommend this string to someone who hits lots of topspins.
From: Steve, Charlotte, NC, USA, 07/10

Comments: I cannot say much about the string since it got eaten up by my Luxilon BB in one long day of tennis. I couldn't really feel the impact of the Tecnifibre with the luxilons. I highly recommend you not hybrid these strings with luxilons.
From: Jonathan, Kensington, MD, USA, 07/10

Comments: I re-strung my racquet for the first time. I rate my self as 2.5-3.0. The stringer strung 2 lbs above the range for max control and less long-balls (which was my biggest problem). I did not like these strings at first, but after hitting for about an hour, I absolutely loved these strings. No more long-balls. I was able to hit my shots with a lot of pace and a lot of top spin for the first time! My hitting partner(rated 4.0) said he noticed a HUGE improvement in the placement and power of my shots. Also, no soreness in the elbow after a 2 hr session! I didn't notice any movement of the strings either. Now...let's see how long these strings can last.
From: XANKX, Los Angeles, CA, USA. 06/10

Comments: I figured all the great comments about this string pretty much had this one covered but following the unofficial TW rule of you hit it you review it I figure I better contribute. This string is AWESOME!!! Love the feel and power of this string but most all the comfort is what really blew me away. I have had some injuries from other sports that made it hard to hit for long periods of time without severe pain in my wrist and hand. Since I've been using this string that problem has almost completely gone away. Also I'm somewhat new to tennis and I didn't really understand the term "BALL POCKETING" until I started using this string. Yes it does fray like a multi and yes I'm sure there are great strings to hybrid this with to increase overall durability, but if you are looking for maximum comfort then this is your string.
From: Dallas, Petaluma, California, USA. 06/10

Comments: I have tested many strings including VS Team. This string is definitely not comparable to VS Team on the "feel" factor side but overall not a bad string. Excellent durability, tension maintenance, ball pocketing, spin and control. But not arm friendly. Mainly due to the fact that you have to string at a much lower tension then usual. I'd say 5 lbs lower for sure. I usually string mine around 55lbs so went with the same number for this one as well. But it felt around 60-62 and definitely not a good feel. So a definite disappointment in that category. I'm switching to 17 gauge version and will string at 50 lbs. I'll post a separate review on 17 gauge string later.
From: Bharath, Hillsborough, NJ, USA. 5/10

Comments: In my humble opinion the best multifilament string out there right now. Still, if you're not a string breaker I would still go for Babolat Tonic+ or VS Team/Touch natural gut. Just like all multis, the Biphase loses tension fast, whereas the natural gut holds tension like no other string.
From: Jon, Genk, Belgium. 4/10

Comments: Great string! Using it on my LM Instinct @ 50lbs. It feels very comfortable on my arm which was the main reason I bought it. It gives me more power, spin and playability is fantastic. I think I'm going to stick to this one for a while. I highly recommend this string for people with tennis elbow.
From: Cristian, Sebastopol, CA, USA. 4/10

Comments: Natural gut has some nice properties like feel, comfort, grabs the ball, and power. X-One has the same properties. X-One is a little firmer than Gut, but for me that's a plus. I found great control with X-One that's kind of hard to explain. I'm guessing it's the consistent feedback I get form the string. I really have no reason to buy Gut now other than wanting a more mushy feeling string that some natural guts offer.
From: POG Mid, Costa Mesa, CA, USA. 04/10

Comments: I thought it was a little too stiff and underpowered compared to NXT. It made the sweet spot feel to small on my 18x20 string pattern Head Prestige mp racquet. Just didn't feel right to me. It's also a little pricey considering you can get gut for just a bit more. Try KLIP Legend if you're willing to pay a few bucks more.
From: nate s, kettering, oh. 4/10

Comments: It took me some time to get used to it, but that could have to do with the fact my stringer strung me at a higher tension than my usual by mistake... but once I got used to it I was very impressed... great control... I was used to Babolat Hurricane and the likes before that so this was really an improvement in control. I just wish it would last longer for the price. Not sure if I will go back to it, but I recommend a test play with it!
From: Marc, Ottawa, ON, Canada. 2/10

Comments: This is the best string I've ever used, it does every thing well from hitting the slice to hitting the kick serve. It hits great topspin which is needed for a modern game. Great string to come in and sneak in a serve in volley every once in a while. The only things I didn't like about it was it isn't very durable and moves frequently. I would give it a 9.75/10
From: Kyle, Birmingham, Alabama, U.S. 01/10

Comments: The string is Ok, but is underpowered compared to the string I've used in the past. It does have good feel and is soft, and it literally feels that you are throwing the ball across the net. Personally, I like strings with a lot of pop, so I don't think I will be using this again.
From: Wilson, New York, NY, USA, 09/09

Comments: I put this in a friends racket because he wanted to try something besides gut in the mains and it broke clean in two places at once! I felt bad because I recommended it and probably will not buy it again, maybe it was a faulty pack or something but it isn't cheap stuff, only compared to gut these days!
From: Rizza, Longview, WA USA 09/09

Comments: I don't like this string, because it breaks very fast. However, the playability is good, but it doesn't worth to restring every 2 days.
From: Tomi, Budapest, Hungary 08/09

Comments: A good choice for someone needing a low powered, very soft string. I strung it at 59 lbs and didn't get too much power, but a nice plush response that allowed me to swing out with confidence. Good choice if you don't want to go poly.
From: Anon. 8/09

Comments: Does not last long at all. I am tournament level junior player and I broke 3 sets of this in a week. I was using this as the cross in my hybrid string blend. I would not buy again. Can't restring every couple days.
From: anon. 08/09

Comments: A nice gut-feeling string without the price tag, but I wouldn't use this as a full, hybrid it with a softer string and you have your self a great string bed.
From: Junior, G-burg, MD, USA, 07/09

Comments: I had this strung in the full bed at 58lbs. The mains were fine but the crosses were absolutely shredded in like 6 days. I was surprised with the durability, it lasted me 2 weeks of playing -- 2 hours a day. It's a good string, but I would not buy it again.
From: Brad, MA, USA. 05/09

Comments: Strung X1 16g at 62 lbs mains with synthetic crosses, tension loss after about 4+ hours, main strings moved a lot after playing with a lot of spin. Previously tried X1 in 17g, tension held better than 16g, less string movement, but too much power. Probably 16g better suited for stringing as crosses.
From: James, Walnut Creek, CA. 04/09

Comments: These strings are not right for me at all. Maybe it needs a break in period, but after hours of hitting I don't like this string. I didn't notice any added power or control. Very disappointing for the price. I'll re-post my comments if it feels better after the first 3 hours.
From: Bryan, San Jose, CA, 4.0. 2/09

Comments: I used this string on my Head Radical Microgel mp strung at 58, and I broke the string within 8 hours time, but... great feel and power. All round I'd rather stick to the Signum pro HEXtreme (orange).
From: Lionel,Australia, Vic, Mel. 2/09

Comments: Bad choice for me. I strung this at 62 lbs. on my Pro Kennex Kinetic 7.0. A lot of the reviews have commented on the power of this string, but I found I had to exert great effort to hit the ball consistently past the service line. In short, not nearly the power I expected. I'll end up switching back to either Wilson NXT or Gamma synthetic.
From: Chris, Pasadena, CA, USA. 1/09

Comments: The X-One Biphase 16's are excellent if you are a player with heavy topspin. Strung at 54 as crosses with Luxilon Big Banger as the mains, the strings lasted about three days with an average of three hours of hitting per day. The mains were broken in and lively but the Biphase's started to wear as if the too much topspin had thinned it down and the sweet spot literally looked like it was made of cloth. The only problem is the durability, other than that, no complaints.
From: Hoang, Piscataway, NJ, USA. 1/09

Comments: Tecnifibre X-one Biphase is a very comfortable string that gives you great power and feel. It's very much like gut as the racket feels like an extension of your arm. Polys generate great spin and last long, but feel uncomfortable. This string gives you a little extra power without the jarring shock of poly. X-one Biphase works well with a closed patterned racket like Head radical. Polys are good if you want a lot of shocking spin and want to save money with it's durability. But if you like power and feel, go with the multifilaments like X-one biphase.
From: Jim, Milpitas CA, US. 11/08

Comments: Very good strings I'm using the 16 gauge. I used to use the big bangers, which is still the best in my opinion. But these to me are good. Very different from bangers. It is easy on the arms and has a good feel. Although I like my strings to have more of a feel to my nblade so that's the only reason why I would go back to those. But don't get me wrong, these are good and I will definitely buy these again, just not now.
From: Dream, CA, USA, 10/08

Comments: I'm using these strings on a LM Radical @ 59 lbs. I came from using Prince Original Synth. Gut @ 60lbs. The strings come in a nice matte black finished package. You could tell the difference in quality from Prince vs. these. Immediately, I felt more bite on a ball, more forgiveness on off-tossed serves and absolute comfort and no arm pains. This string is the one for me! I was surprised to see how much different hitting with a more expensive string could do for your game. My philosophy used to focus on form determining your quality of strokes. But I now know there's only so much form can do before you take a step and upgrade your equipment. To compare and contrast, you can drive well in a Honda Accord. But when you take a drive in a 400 hp Lexus ISF, you notice that your whole driving experience opens up. In this case, changing my strings to X-One Biphase, my serves had more spin, more speed, more pop. My groundstrokes land deeper and I can see more prominent differences in hitting flat versus spin. Amazing string.
From: Robert, Los Angeles, CA, US. 9/08

Comments: This string is closest to gut like performance for a lot less money. The playability is awesome as there is plenty of pop and ball bite. In addition, this string is very easy on the arm. I'm currently using the 16 gauge version in my Volkl C10 and plan to continue doing so. Tecnifibre continues to make one of the best synthetic strings in the world! Kudos to Tecnifibre!
From: Ken, Brooklyn, NY, USA, 09/08

Comments: Love it. Very easy to string, gut-like performance, very solid contact. Just switched over from Luxilon BB ALU Rough. The string destroyed my arm, so I looked for a different string and found this one. Very soft on the arm and the durability isn't bad at all. A little fraying after 10 days of play (3-5 hours a day). Overall, I love this string and the potential is limitless. If you choose to buy the string, try and notch it toward the higher tension range.
From: Cooper, Syracuse, NY, USA. 8/08

Comments: Great string overall. I strung it on my Head Microgel extreme pro at 61 lbs and after a week, I still don't see any signs of wear. I found that the strings also provide exceptional spin and a feel comparable to natural gut.
From: Brian, Centreville, VA, USA, 08/08

Comments: Personally I find this string to be great especially considering its 16g. I found above average spin and a wonderful pop off of them, and after almost a month, there's barely any signs of wear or drop in tension. When I'm going to restring my racket I will try it in 17g and compare, but so far it's my favorite string to date.
From: chris, marengo, IL, USA. 8/08

Comments: Great string with the Head Microgel Radical. Gives the right spin with the power. Also has ok touch. So buy for Head Radical.
From: Justin, USA. 8/08

Comments: So far I'm really disappointed with these strings. After all the hype and good things I've heard they just didn't work. I did not get much spin which combined with the loads of power equaled many unforced errors and they added a ton of weight to my stick (12.1oz-12.6oz a full half oz). On the positive side the extra power helped me bang in some heaters while serving and I have never tried a more comfortable string in my life (not even natural gut). Overall it is a great string just not the one for me. I normally use Prince lightning xx 17g so I may pick up a set of these in 17g and see how I like those.
From: Daniel, Mililani, HI, USA, 06/08

Comments: These took me a day or two to break in. I don't hit hard normally, but my friends do. Once they break in, they feel good. This string is more powerful compared to the NRG2. More crisp impact, but I liked the feeling of my NRG2s more. Probably just me. But if you want more power, these strings are for you.
From: Li, NJ. 6/08

Comments: I strung two racquets with this strings as crosses (poly mains). The first one at 57, second one at 60 and I could not control the power of this stuff. The balls were flying all over; don't like it at all! These are very bad strings, too much power, trampoline effect, no feel, what else? Keep away of these, don't throw your money away
From: Blackfrido, USA, 04/08

Comments: This is an excellent multifilament. I have also used Tecnifibre's NRG2. I tried both on my Wilson nSix- One 95s, both strung at 63 pounds. I'm not sure which one I would prefer, though, as both are excellent strings. Both also had surprising durability for multifilaments. I think the X-One Biphase gave a little more spin. So if I had to choose one, I think I would go with the X-One Biphase. But I would recommend trying both and see which one you like better. I don't think you can go wrong though with either.
From: Atul, New York, NY. 3/08

Comments: I think I agree with Thomas below. Too much power. I dialed up the tension as much as I could and still needed to dial back my groundstrokes. I lost a bit of control and feel on the slice and volleys. Maybe with extra tweaking I could find the right balance, but the Wilson NXT and Tecnifibre NRG2 suit me the best. My humble opinion - if you ever want an all- around game, stay clear of this string. If you like to simply bash from the baseline, want some extra juice, and are OK with leaving the touch and feel shots in the quiver, this string is an option to consider. Otherwise, those precision shots may suffer because the balls do explode off the stringbed.
From: Joe, San Diego, CA, USA. 3/08

Comments: A good string overall. I liked how it was nice in my hybrid with Luxilon Power Spin 16. This combo offered very good topspin and power. Everything was exceptional except for my volleys, which were a little overpowered, but nothing a little practice won't cure. Overall, this is a great string for the three hours I played with it. It is threading already just like gut, but not as bad. Gut broke way too fast -- only 5 hours -- which was ludicrous considering I spent 30 bucks on it. This will last another 10 hours judging by its current condition.
From: Anon. 1/08

Comments: I was using Babolat Pro Hurricane Tour, but it was killing my elbow. Now this stuff is incredible! Freshly strung, it's very powerful, but pockets the ball so well that control is perfect. It doesn't dampen vibration as well as I'd like, but of course a nice "US OPEN" dampener takes care of that. Highly recommended.
From: Alex, The Woodlands, TX, USA. 1/08

Comments: I use ALU Rough crosses and Babolat gut mains at 60#. More powerful than gut, and 1/4 of the durability. Going with poly crosses gives you a much stiffer, more control oriented stringbed than poly mains. I went through 4 sets of this string to just one of my gut. I play with a Flexpoint Prestige MP, so my strings last much longer than in other racquets. Because of that, price isn't an issue. I like the string just fine, but it is not a substitute for gut.
From: Roy, Santa Rosa, CA, USA, 08/07

Comments: Exceptional string. Very responsive, very good feeling, good spin and high precision. Average durability but very willing to have average durability for the other exceptional qualities.
From: Anon, Switzerland, 07/07

Comments: The string does have a nice feel to it but different. Way too much power and it just didn't produce the topspin control that NXT does. I'm going to stick to NXT. Pure Drive 60#
From: Thomas, Evansville, IN, USA, 06/07

Comments: This string in term of feel and durability are much better than Wilson NXT Tour 16 that I had before, it hold the ball longer, and better in control. I string at 59 pounds on my Prince Tour Graphite Classic Original Mid.
From: Ken, Cypress, CA, USA. 6/07

Comments: Strung in a KSix-One Team at 55lbs. Way too powerful, too springy, too slick. It might be OK if you want to string at the maximum rec. tension. But I'm switching to something crisper (original sensation, which came in the racquet, is much crisper) with much better durability. At 14.50 a pack, don't expect a miracle: it's an elastic multi that will fray very quickly.
From: JD, Brownsville, Texas, USA, 06/07

Comments: For power and feel this is the best string out there - plays like gut. I've tried all the strings in the comment below, plus more. I've also tried a number of polys and hybrids. As far as control some of the polys may have the edge, but if you don't mind some power this string is the best out there.
From: Ryan, Redondo Beach, CA, USA, 06/07

Comments: This is the best string I have tried so far. I have gone through many multifilament strings, NXT, NXT Tour, Bab. Excel, K Gut, K Gut Pro and VS Gut and none of them hold tension as well or as comfortable as X-1 Biphase. This string holds up to all good comments mentioned in my opinion. KFactor Six-One 95 at 57lbs.
From: Brian, Laguna Niguel, CA, USA. 5/07

Comments: Looks like I am the only female. I tried NXT before and loved it a lot, so I loved multi's. And then I looked for a much better multi, and found biphase. I strung it at 56, pretty stupid. And I also had lead tape on my racquet. And my shots very going out, so I ripped off all the lead tape on my racquet and the power went down. And is the right power to me. This is a great string. My string started to fray so I invested in some string savers. And love this string a lot. A perfect mixture of Power, Control, Comfort, spin. Love this, and for sure use it again. Next time I will string it at 63.
From: Kathleen, NY, USA, 03/07

Comments: Yep, this is the string. Outstanding power and control. Feel is not quite as good as some of the Babolat strings, but all things considered (incl. durability), this is the best I've used. I've had it in my Babolat Aeropro for the last year. I agree with an earlier comment: string toward the high range for best control.
From: Brian, Mill Valley, CA, 03/07

Comments: Unbelievable, you cannot get a better string than this. I used gut before, but I love this string more than the gut and it's half the price of gut and it's as good as gut. I love this string more than NXT, and NRG2. I got excellent amount of power, perfect control, 100% comfort. I have tennis elbow, and after a session I felt no pain in my elbow. My backhands were much better; my serve is way better. I say this is the best string I tried in 10 years. And I am shocked I didn't come across this earlier. If you like NXT, and NRG2 and thought that they were awesome wait till you try this string, it will just blow you away. I was 200% happy about this string. In this review people were unhappy about was the durability, I solved that by investing in string savers, so the durability increased.
From: Andy, NJ, USA, 01/07

Comments: I have to say that this string blows all strings out of water. I have never hit with a string with more power, control, and feel. I mean the power and ball striking you get is incredible. On serves, the ball just explodes on kicks and flat serves. The strings don't move, so its kind of like big banger in that there is controlled spin. I have nrg2, which is outstanding, but this is a step above. This is worth the extra 2 bucks over nrg2.
From: Colin, Alaska 09/06

Comments: I strung Luxilon Big Banger Alu Power 16 on my Pure Drive Standard because I heard it was a good string. It was durable, but it was killing my arm. So, I decided to cut it off and put new string on. X One 16 is a really nice string. It gave me drastic improvement on my strokes and especially my serve because this string has a lot of power. Don't get me wrong; it doesn't make your racquet a springboard. I've played with this string for about a month, about 4 or 5 days a week, and the string is still good and still has power. The string started to move during the beginning of the 3rd week though. X One has excellent feel, power, and comfort, but it isn't good with slices and drop shots. While it is still possible to do a decent drop shot or slice, its thickness, most likely, makes it harder to do good slice and drop shots. Nonetheless, this is a very, very good string.
From: Jacque, Seattle, WA, USA 07/06