The 450R is a light weight RACE quad... the 700XX is a heavyweight eat (almost) anything and do it fast quad... a comparison would be to the Raptor 700, which has NO ground clearance, but stears much nicer. The XX you have to be able to ride to ride it well, if you wuss out in second gear on the trails then you will hate it.. but if you want to go fast and can lean the turns and keep the throttal up, then you will love it.