Yes I have it, it works very well, as in I've never chopped a ball. Basicly the only difference it makes is it puts a dent in the ball when you shoot it (thats if I has to be used.) I have also done things like stick my finger in the gun and let it "chop" my finger, lol pretty stupid, but it dosent ever hurt if you do it, the bolt just stops, like its suppost to. It works very well, I have set my board to 30 bps with a grav. hopper and shot full auto, it will only fire a ball every other shot, lol, but never chop.
The best part is it isn't a problem to use or own. U wont even know its there if you dont pay attention. You dont even have to re cock it if it engages. But it does its job, and well. And it takes NO extra effort to have. Just like everything else Tippmann makes, you can focus on your game, not your gun.