Strung up 2 AeroPro GTs w/ this combo. One at 24/22 (kg) and one at 23/21,3kg. Multiply by approx 2,2 for lbs, 24 kg is (almost) 53 lbs. Played indoors in coldish conditions w/ old balls (w/ coaches doing drills), a bit of an off day, but the 24kg mains felt boardish and stiff, no bite on the ball and generally dreadful to play with. I held off on changing racquets to avoid looking like a poof wannabe, thinking it was me rather than the setup responsible for the major suckage on display. ;-) I caved in finally and had a go w/ the 23kg mains, and to my surprise it was miles better. I am starting to think that the Babolat BT7 gut is made to play better at lower tensions. I´ve been playing with (old) VS, Tonic and Pacific Tour Gut at similar tensions of late, crossed w/ various poly´s (Alu, Hyperion, RPM Blast) and I have been liking the experience. However, the BT7 formula seems to have thrown my tension preferences for a loop. Either that, or it has turned the Bab gut into rubbish. Will try this setup at lower tensions as well and see how it goes. The jury is out on the LTec 4S. My first impression is that it is completely underwhelming and does not do a good job as a cross for gut mains, but I will not conclude before I´ve tried lower tensions. At 21,3 it does not seem to allow the 23kg gut to slide and snap back enough, but being a softer poly I think the tension difference is spot on. It is a lot worser wrt snap back in the 24/22 setup. F.