I own the ´07 NINJA 650R & must say I LOVE IT it keeps up with or outruns the other bigger bikes has better handling & sleeker style than many of the so-called superbikes this machine is probably kaw´s greatest accomplishment up to date i´ve changed out the carbon fiber exhaust back to factory & yes it´s much quieter BUT, seems much stronger. Most people don´t understand (as i didn´t) when changing exhaust on these bikes & ALL OTHERS for that matter you MUST add the PCM \