Has anyone seen a review of different mufflers, like the FMFs, WBs, DGs, etc. comparing HP gain, noise level, that kind of stuff? I'm interested in a new muffler for a 400ex. The FMF IV(2) has me interested, but it says it's quiet as stock, and while I don't want it to be too horribly loud, I also don't want the thing to sound stock. Any help?