Leo Vince isn't a bad exhaust. I wouldn't use it on the People 50 2t because the gearing (due to large rear wheel) makes it really tricky to dial in. Super 9, cobra, Vitality, etc are perfect candidates for an expansion chamber though. You'll want lighter roller weights and different clutch springs to go with it to get the best benefit. Your engine will rev higher with this. If set up correctly, it will perform better than it did stock. If you just bolt it on, more times than not your low end (off the line) performance will suffer.
~Josh