I have an '06 WR450. Last bike was an '04 300EXC.
The KTM turns sharper and is easier to throw around in tight woods. Good race bike if you can deal with the vibes/arm pump. The vibes on the 300 caused nerve damage in my hands. Shut me down for two years.
WR450 gets better traction, less deflection, smoother motor, better straight line stability but takes more muscle to move. WR needs major suspension work to be on par with the 300.
With a good suspension overhaul, I feel that I am as fast on the WR as I was on the 300 in most situations, It just takes a different technique. I have more fun on the WR and last longer because there's less arm pump. I also find the WR easier to ride because of the traction.
The 2012 model may fix the two biggest gripes with previous WR's - slow turning and weak suspension. The weight is still there. It will be interesting to see what the pro's do to lighten the new WR. Australian pro's Matt Phillips and Daniel Milner will be racing the AORC on the new WR. First race is 2/25/12 -
http://maddixpark.po...lian-yamaha-off