Well I got a prochamber with my flows and it sucks. It's WAY too quiet and has absolutely no "scream" too it. The deep echo-ish tone is definately killer, but I think the flows are the ones responsible for that not the PC. While the tone is cool it's too quiet when cruising and at WOT it isn't very impressive either. I was thinking of switching to an H pipe.... BUT I hear the UPR X sounds awesome with flows. Anyone runnin that setup? Does it sound muscle-car deep? How bad is the rasp? thats the one thing im really scared of, I drove a stang with an X once and the rasp was VERY loud inside the cabin, it drowned out the actual exhaust note when accelerating... i don't know what kind it was though. How is the UPR? Its that or an H.