Well my wait is over I was able to swing a leg over a buddies 2010 450f today and it was great to see what all the fuss is about. I'm a vet expert with over 20yrs ridding/racing experience. I currently have a 2007 rmz 450 (interm bike, while waiting for my yz450f to arrive) My last bike was a 08 crf 450, I've ridden all the 09 450's and 08's except the ktm. The first thing you notice with the yamaha is the instant throttle response, it is too abrupt and needs a little fine tuning. I would guess a remap would help. Power is good, very strong down low and in the middle, but seems to go flat up top, short shifting is recommended. The power is easier to use then my 08 crf but the bike signs off much sooner and doesn't feel as fast as the honda. (I have yet to ride a stock 450 with as broad and powerful motor as the 08 honda 450) Having said that, the honda would wear me out, it was a handful and when you got tired it was not your friend! I think the yamaha will be less of a problem when your tired. Which brings me to the 1 major element of the yamaha that really left me thinking, The bike requires so little effort to change direction or initiate a turn that I could put many laps togther and still feel fresh. This bike rides so light that it requires much less energy to ride, it will be an advantage for most riders. The bike realy turns well and tracks straight. It turns as well as the suzuki(which is the best turning 450 IMO) and feels soooooo much lighter, almost 250f like. The suspension is the best stock stuff I've ridden since the first year yamaha 250f (it was magic!) The brakes were good, ergos were great. The bike takes a while to get use to it is so different then all the other 450's (09 honda is the most like it) it is a unique bike. Hope this helps.