i have it on,, it's not tha big of a deal to switch back and forth,, but it's louder then stock,, you hear the engine more,,, not sure what it did to the pipes but they also became louder,, so it seems. But for power,, well i had to add about 5 grams of weigth in the heal to get my RPM's ,, and it does pull harder the sled that i test against is about 3 sleds behind now,, and the driver of that one is a little guy compared to me,, hope all helps.