i work at a bike shop, we do performance mods and sell accesories, we also have a bike dyno. the yamaha YZ450 lays down 1 or 2 more HP than the CRF450 but the curves are a lot different. the CRF is a lot smoother than the YZF and easier to ride for some. i personally prefer the CRF over the YZF, especially since i ride the dez and the YZF has the 4 speed. i wouldnt even consider the WRF because of the e start and head and tail lights. right now i have a Husaberg FC550 with a little bit of motorwork, lays down 51hp on the dyno, and it has a 6 speed