This is a subject matter that always never has a good answer depending if you want a pipe or want quiet.....it is a no win situation. Since the sound requirements are what they are, and getting tighter next year, just be smart in your purchase decision. I know what pipe I am going to buy and that is what it is......the stock pipe in my opinion is lacking in performance as well as weight - it is a boat anchor! If you are the "Avg. Joe" rider,stick with it.....you won't ever see or feel the difference.