KawiDave - I have, through the past three years, had experience with all of the pipes mentioned here. I'll give you my take. I've run both the rev and torque FMF pipes. Both of mine fit fine and work much better than stock. I then tried a DynoPort pipe. It is made of heavier material and is an awesome ( mid to up, MX style ) powerhouse of a pipe...one drawback...it is very large and exposed to damage in the lower sections. I've finally settled on the Pro Circuit Platinum II. This is my favorite of all pipes for my style. It has great roll on for tight trails, and produces great power all through the rpm range. Other bonuses were great construction and easy to jet for. My rankings are #1 Platinum2 ( the 2 is important) #2 DynoPort - great power, #3 FMF gnarly, #4 FMF rev ( the FMFs reverse order on 220s)