You should go on youtube and check out 21stCenturyGunfighter where Stephen Pineau does a 5 part series comparison on many of the available muzzle devices out there. It is really a great comparison, I highly recommend it!
You should try it.
NOT a tacticool showpiece. This is for multigun competition (M4 carbine copy) and I want something that WORKS, not something that looks like it came out of a video game. I've seen good reviews on the AR-15 Miculek Compensator. Any other ideas that work well?