I've been playing with Gamma Ruff for years and I've decided to transition to poly strings. I hit with Gamma Zo Twist recently and I was hitting the ball just as well (or not well) as with the Ruff. I did notice the Zo Twist held up better than Ruff which tends to get pretty beat up after a couple hours of hitting, although I broke the Zo Twist before I noticed any tension loss. I'm mostly looking for durability but performance is important too. I want to try some others, I've heard good things about Spiky Shark, Signum Pro Tornado, Black Code. How do those compare with Gamma Zo Twist?