Comments: Strung it in an 18x20 Prestige at 48 lbs. Plays real well. May well be the best multi I've tried yet. Feels real good on all strokes. Very expensive. Not sure it's worth the price.
From: David, 10/20/17

Comments: The string is not durable at all. I had it strung at 56 pounds in a full bed. The string started fraying after playing for 2.5 hours only. I enjoyed it but durability is an issue. I will be trying HDX Tour next which is a multi filament and see how long would it last. I recently tried the NRG on the mains and ALU (luxilon) on the corss. It lasted me 3 weeks.
From: Amardeep, 8/23/17

Comments: I've tried many strings. Polys, gut and hybirds. This one is the best in my opinion. Power, feel, touch and nice acoustics. I string all my racquets with it. I have a PD strung at 54 lbs. Before that I had a Blade at 55 lbs. Turns any racquet into a formidable weapon. Never had any problem with durability either, but then again Im more of a flat hitter.
From: Jon, 5/15

Comments: Great feel on a full bed. Very good power. Technique must be sound to get heavy topspin or spin on serves. Some danger in balls sailing long, so best not to go below 55 lbs in tension. I prefer to use it as a hybrid mixed with a spin friendly poly. I'm a 3.5 NTRP league player. I like to hit big kick serves and topspin forehands. Playing with a Prestige MP.
From: Gabe, 2/15

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: Strung X1 16g at 62 lbs mains with synthetic crosses, tension loss after about 4+ hours, main strings moved alot after playing with alot 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: 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 pound on my Prince Tour Graphite Classic Original Mid.
From: Ken, Cypress, CA, USA. 6/07

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: 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

Comments: Amazing string. I would not have tried it because of the price tag but ordered a used racquet off the boards and it came strung with this. Amazing power and comfort. Great control and feel. I definitely recommend it. Once I become manager of my McDonalds I will definitely be ordering my own packs.
From: Mike, Milwaukee, WI Usa 07/05