I have a 2007 Honda 450x and my buddy has the 2008 WR450. Both bikes are great but definitely have distinct characteristics. First the Yami is better in mountain conditions, more of a technical bike. The Honda excels in desert riding. Anything with high speed, whoops, sand, etc.. Yami engine has a great powerband, hits a spot in the rev where it really picks up speed towards the top end. Yamaha is a bit more controllable and doesn't have as aggresive of a hit. Honda has power everywhere. Don't believe me... ride one. It will want to pull your arms out the first time out. Overall I would take the Honda, but the Yami has its place and is a great bike. Every bike has its issues and valves is one of the things people say about honda's but the valves are cheap to replace and shouldn't deter anyone. Change the oil often and many bikes have gotten thousands of miles before having any issues. Lastly, I'm partial because I bought the Honda. But my buddy refuses to switch bikes now because he states he likes the Honda more. Someone mentioned this before but the Yamaha doesn't turn well and that's his complaint and positive when comparing to the X. He has since sent his forks off to Racetech for the gold valves and spring which did make an improvement on bottoming resistance.