I previously used Tecnifibre NGR2 17 and X One BiPhase 17. The Bi-Phase One wore out quickly on my Prince Premier 105 Racquet which has a 14x16 very open string pattern (tension 62, this is a high tension racquet). I tried the Head 'comfort' Sonic Pro 16 on this same racquet, but it felt a little stiffer (I have a tendency to get tennis elbow) and I did worry about it although it never got as far as getting tennis elbow again. I used this string (HDX Tour 17) on my new Prince Warrior 107T racquet string pattern 16x19 tension 57. I did not see any major improvement in Power or Spin compared to the NGR2 or the X One Biphase. It looks more durable, time will tell. I used the 'comfort' Volkl poly Cyclone Tour 17 G (same tension) on my spare Prince 107T and its a fabulous string: more power, great control, more spin, more energy return, more pop on serves and crisp volleys and solid ground strokes. It++Ǉ+̭+G+ half the price of the HDX Tour.
I have used16 g NRG, 16 g BIPHASE-One and 17 g HDX. All are great but HDX has the most crisp feel of all. There is more than enough spin and power. I used the 17 g in the HDX since there are polyester fibers in this multi (along with polyurethane and elastyl) hoping to achieve a little more playability and comfort. Mission accomplished! 4.5 player, yonex vcore xi 98 ,57 lbs
Great string, great ball speed, very accurate feel , lots of power . 2014 BLX 18x20 strung at 54 mains 52 crosses priviously used Razor Code 18 with Gamma Glide this string will help take your game up another notch on all levels try it you will be pleased !!!