I pick the YFZ, because I own one, the seat is harder, and thumb throttle is a biotch, but the power is worth it, I just got a thumb extender, and got a seat cover with one inch of foam. I have satten on a 450r, it was kind of weird to my YFZ, just feels alot different, my cousin, who I told to get a YFZ, doesnt really like my YFZ, so he sat on this guys honda in the cam we were staying at, and he liked the hondas postion, so he is going to try to get one. Also, why would you say the hondas carb is smoother, the yfz carb is actually smoother, its a FCR, and their one of the best name brand carb. I would think if honda changed the carb on the 450r to a FCR it would probably keep up with a YFZ stock, and piped vs piped. Theres my opnion on this subject.