I have an '06 YZ450F, and my buddy has an '07 WR450F. I rode my buddies WR450F and a '06 YZ450 before making my decision. Once you get the WR unplugged it does pretty well. But WR power is boring to me, which is good for tight trails, but at the same time, I like the hit of the YZ power when trying to seat bounce big whoops, and pivoting corners, and breaking the back end loose. The WR has too light of suspension. I'm lighter then my buddy that has his WR, and he completely bottoms out on the lip of small jumps without even getting air born yet. Just a few experiences but bottom line stats IMO: WR goods -Electrical(odo, speedo, elec. start, headlight) -18" rear wheel -stock spark arrestor -wide pegs -soft suspension -bigger tank -kickstand -Transmission WR bads -Electrical-More shit to brake, fix etc -Weight -Needs uncorked before enjoyable -Suspension is soft, but TOO soft -Not exciting to ride YZ goods -Motor -suspension -Light as hell -Can easily be made into a WR eater on the trails. YZ bads -No electrical -Smaller tank -Doesn't have any of the things that make the WR good, but doesn't have anything the WR has to make it bad either. That should tell you it's like comparing apples and oranges, it's just you can make a YZ into a trail beast way easier then you can make a WR into a descent MX bike. And a WR doesn't even come out of the box as a trail beast, you still have to get your handguards, rid the plastic skid plate, and unplug it.