Comments: The term "pleasant surprise" is definitely deserved. Seems to do everything nicely for a pretty decent price.
From: Noel, 5/12

Comments: I was pleasantly surprised by the performance and durability of this string. I have no problem generating spin and I like the combination of control and power I get from this string. It is stiff for a multi but that is one of the reasons that I like this string, because it does not get mushy/trampoline like. I had this strung on Head Speed Pro at 58 lbs.
From: Malik, 7/11

Comments: I love this string. It has great control, power, and maintains tension, easy on the elbow. After Tecnifibre discontinued the TR PRO, it took me two years to find this string, which I like even better. It is very gentle on my elbow. There is plenty of pop on my serve and excellent touch on my volleys. Frankly I hit a pretty flat to slice ball, so I cannot comment on spin - I certainly get bite on my drop shots and drop volleys. I am a good 4.0 doubles player with a Volk PB3 110 square in strung at 60 lbs.
From: Mac, 7/11

Comments: I love this string. I put 2 lbs less than normal on my Head Prestige (64) and it feels great. A perfect balance of power and control and it feels like the sweetspot increased in size, no hard vibrations if you hit outside the center. It also gives me plenty of spin
From: Herwig, Valinhos, SP, Brazil, 11/07

Comments: Have tried both 16 and 17 gauge. 16 gauge lasts a tad longer, while 17 gauge is noticeably livelier. Prefer the 17 gauge: the livelier feel of the 17 is worth more than the bit of extra durability of the 16. Others comment that the 16 feels dead; while this may be more or else true, control is not lacking in the 16. The 16 allows you to get out of the stringbed only what you put into it, not more or less--the stringbed (and your shots) becomes predictable this way. Reducing tension could add pop. Both play best newly strung and maintain tension noticeably thereafter. Vibration is somewhat muted on both versions (less muted on 17). One could actually play without a vibration dampener. This quality may help the elbow a bit. The 17 has all the benefits (tension maintenance and muted vibration) of the 16 with the added benefit of a livelier responding stringbed. They are both control strings if you know what to do.
From: Jim, California, USA 01/06

Comments: Well, my first impression is that it plays like kevlar without that pesky durability. Spin production is weak compared to my regular string, Gosen OG micro, and I didn't like the stiff feel. I'll give it a few more sets before I cut it out, but isospeed energetic is probably not going to be one of my favorites. I'm a 4.0 all court player using a prince thunderlite mp, strung at 63lbs.
From: Peter, Coos Bay, Oregon, USA

Comments: At first, I thought I had found the perfect string. It feels good, got lots of spin, and lasted a long time. However, it was too good to be true because after a week, my arm was hurting so bad I thought it was going to fall off. Back to the drawing board on my search for the perfect affordable string.
From: Michael Tomlinson
5.0 USTA Ranking
Head Ti Heat Comfort Zone