I had been using Bab Tonic 15l/ Sweet 17 at 60 / 58 lbs. I am now using GG 15/ Pro Suplex sys gut 17 at 58 / 56. Like the ends on the strings being pointed, on the other hand the thickness is not the same all over. These strings play much firmer than Tonic or Klip. Will drop 2 pounds next time. The really big difference is the lack of pop. All my shots drop short. I must learn to take a bigger cut on the ball. This could be a big plus. After 12 hours, no sign of wear. Stringing went well. If I can get 30 hours out of these, my other 4 and half set will take me to 2011.