To keep the stocker exhaust or not, that is the question. There is no correct answer as either stock or other vendor can is perfectly acceptable. The stocker is quiet and there is something to be said for that. There is a definite weight savings in removing it, although the performance gain is negligible. My Area P is louder but then I wear earplugs and can't hear it for the most part. My advice for those that want to remove it is to keep it around and put it back on assuming you sell the bike at some later time. Sell the non-stocker separately. Mine is hanging around in my garage, not that I'm going to sell in the near future, but I might, who knows?