I was looking at a recent issue of Dirt Rider Magazine where they test most the major brands of aftermarket pipes on a CRF250 Honda and a KXF450 Kawasaki. In testing each pipe they ran them on the Dyno and then show the H.P. and Torque curve next to the stock pipes performance. Some of these pipes didn't produce as much H.P. or torque threw most of the RPM range as did the stock pipe and the ones that did, did not show much of any increase. For instance, the stock KXF450 has 47 peak H.P. and the best a aftermarket system could do was around 50. I am looking for input as far as anyone's experience in what a aftermarket pipe did for them. Did it mostly just make your bike sound better/louder and gave you the illusion that it ran better/quicker or did it give you very noticeable seat of the pants performance that you were able to compare next to your buddies bike by how much better it pulled or not. I would spend the extra bucks to buy a pipe if I thought it would be worth it. Sorry about the lengthy question but if anyone has some good experience on this subject that they could share I would appreciate it.