Mine performed fine with the FMF that came on it for a long time. But my issue with it was the powerband it created. The specialized riding I do requires a pipe which can have the throttle chopped (to maneuver or climb over obstacles) and then be able to get back on the pipe (while under load) to finish my climb. If all I did was ride on dirt I probably never would have been unhappy enough with the power the FMF pipe gave me, to go looking for other options.