I used to have the Brospeed, but I sold it for a cutom 2.5"/Brullen dual tip muffler setup. Actually, I had the Brospeed (when I bought the car, from the dealer) and added a 2.5" mid-pipe to it later on. The mid pipe helped alot!
But after the new 2.5" custom exahust, I feel a bit more power. The Brospeed is mostly for looks/sound. the piping is like 1.875"-2"...not a big help with flow.