Just got these (16L @1.25 mm) strung on my Prestige 360 Tour (18x19 string pattern) as the mains at 57 tension and used Tecnifibre NRG2 (16 @ 1.32mm) for the crosses also with 57 on the tension. Got it professionally done at a very reputable place, that also had this string in stock so they must of been familiar with it even though it's a newer release.I'm a level 2-3 player, but have pretty good power and randomly hit shots that you'd see with a level 4-5 player. Point being this is supposed to be for all levels and the string after 2 hours of medium power training are already being broken down by the crosses as if they're melting into them. Mind you I'm in the desert playing in about 105-110 degree heat. The NRG2's are a soft string too, but these look like they about to snap in the next week. The NRG2'S look unphased.I consider this a manufacturer defect and will be returning them, or what's left in the set which is half.Feels great hitting with the hybrid setup but no way is this normal within 2 hours. I think it's the heat. Which I guess is the flaw in this string.I specifically got this set-up for working on my serves for the next 2 weeks. Preventive measures for protecting the arm. My setup for overall training is much more control oriented, a bit lower tension for a more durable string on the main (Ashaway Kevlar @ 17) and more harder multifilament on the cross ( Head Rip Control @16)....for this setup I have the mains at 53 and crosses 55. Hard on the arm but last about 40 hours of serious ball machine training. I'd go lower on the main next time for serves, Kevlar is no joke but wow does it last and create spin unlike anything else....heard about Agassi using it and I tried it and liked it. But again, not arm friendly, especially for heavy hitters on serves in training, I'd definitely being the tension down to about 48-50 next time.Peace and Happy Tennis Y'all.