Got a few laps under my belt on an '06 KXF 450 today. I felt right at home when compared to my YZF ('05). I think the KXF probably turns quite a bit better, and the power is smoother on the bottom without much reason to rev it higher. Other than that, I felt like I was on my YZ. I couldn't tell much difference in the jumps with it, suspension wise or weight wise.... I'm very curious to see if any problems come from them this year. All the bikes are getting so good anymore, I wonder what's next?? They've got all the power we need, better suspension than we've ever had before, excellent brakes, mild manners in the air....the list goes on. Fuel injection is obviously the next big thing to hit mx, but besides that, I'm at a loss for future improvements the big manufacturers will be spending their R&D money on. It's a great time to be into this sport, that's for sure!!!