I have been told alot about them from alot of guys . All have been bad things said . my polaris dealer said not to buy just a big thing of junk of MX .. I talked to a few pro races and they said it doesn't jump right and dosnt have the power , and they also broke a few parts on them.. as for KTM i have seen two of them break one was a stock a-arm off of a little 40footer and the other was a stock steering stem off a 50footer .. I have talked to so many races and alot of them said they would ride the yfz450 over most other 450 2nd was the LT-z450r then the Honda TRX450r.. I race a YFZ450 for flattrack and Mx ... Look for a used race ready yfz450 my freind just picked upa a pro AMA MX yfz 450 for 5500$.. Axis shocks . Walsh a-arms sub frame , LSR axle ect its got the best of the best on it