I have a 00 426. The best mod I did was the 03 cam. No more worries about the bike stalling, especially over a jump. Large double, bike stalls=bad things. scarey memory. I really would like to buy an 06 450, but the 426 just keeps going. Oil changes and keep the air filter clean, a semi annual spark plug. It starts so easy and has a ton of power. I ride Mx, most of the time, and It would be nice to get a new bike, but the 426 is not holding me back skill wise. Anyway, I think of it like this. I can be a slow rider on an aging 426 or I can be a slow rider on a shiny new bike. Actually, I have been thinking about picking up a newer 450. The 06 bikes are so good that there are a lot of used 04s and 05s for sale.