I ride my brothers xr400 and love it. It is pure woods riding goodness. The brute force of the 650 is a thrill, but where we ride, the 400 is actually faster and easier. I tear through the woods like wudy da wabbit. For only 30 lbs difference, it feels like 100. I have a recurring urge to swap my 650R for one. Is there something wrong with my head?