I ride SETRA Enduro's on an '03 WR450 and it is a bit of a handfull. I finished the Gobbler Getter at Perry Mountain and I wished I was on a 250. The hills were super easy on the 450 but as you know almost the entire 60+ miles were 32" wide or less. I'm riding the Cherokee National next month and I'm thinking of riding the ole'KDX 200 just to save some energy. I love the big 4 strokes because I'm addicted to the power. I have been looking into a new KTM 400 or if the '06 or '07 WR450 truly has a lower center of gravity and doesn't feel so top heavy and really work you in the single track I will go with a new Yamaha. Yamaha has set the benchmark for their 4 stroke motors and the power delivery is like an electric motor it just pulls so nice once you tune the hit out. If the CG is lower on the new ones like they claim I will get another WR450. My brother acually rides a WR 250 and its a girls bike until you get in the tight single track then it really shines. If anyone out their has owend and raced an '03 WR450 and has moved on to an '06 WR450 I would really like to know if is less tireing to ride and can you flick it about amongst the GA Pines.