The R/SXV's are in a whole other class then the 690/630's. We're talking 10 - 15 HP more and about 30 lbs lighter. Of course that fire breathing HP comes at a cost. My SXV popped a motor at 2500 miles. Oh and I would never consider the SXV for racing. It'd be my KX450F all the way. In fact I set it up to do some sumo racing but then other things came up.