I too just bought a new 09 Kx450f and find it pretty amazing! I have been racing a Kx 250F for the last 4 years (05) and really loved it but even with the 290 kit it was at a disadvantage. I had a 2004 honda 450F for two years and then 2 strokes before that. With the new 450 I recently raced the Old Timers International in Fernley Nv and with only two hours break in riding I did fairly well. The only thing I have changed (due to constant front end washing on the Fernley sand track) was to replace the front with a 756 Dunlop. Everyone on T Talk advised to replace the stock 742 immediately but I had to find out the hard way! Anyway, I love the bike, the motor, the suspension. Just need to get it to turn like the 250!