Originally Posted by bross
All those bikes you mentioned that improved with a new exhaust are at least 10 years old or more. Maybe back then you'd see an improvement but today's stock exhausts are pretty damn good at flowing exhaust gas, they have to be. Only reason to change an exhaust IMHO is for sound or a small weight saving, but hey lets face it, most of us on here could produce a lot bigger weight savings going to the gym, me included.
My TDM was 7 years old, my Dakar is 6. Both benefited from slip-ons. Didn't dyno them but felt a clear difference in performance. Doesn't matter if new bikes can flow exhaust better, they are still restricted for noise and emissions reasons.
I also like having a louder than stock bike, makes lane-splitting safer...