my experience with the jetchip was that it helped make the pedal much more peppy, improve the smoothness of my shifting, and helped keep the proper gear longer (instead of getting "caught in between gears"). i am trading my 300c tomorrow and have removed my jetchip if you'd like to get one cheap to try. it is listed here,
http://www.300cforums.com/forums/par...rts-cheap.html