The 2008 WR250R and WR250X aren't anything like the existing slew of 250cc 4-stroke machines from Yamaha. The familiar WR model, the 250F enduro, has a totally different engine, chassis, suspension, computer, seat, you name it. The same goes for the YZ250F motocrosser which is even further away in the Yammie quarter-liter lineup.
Go to MotorcycleUSA.com to read the entire Yamaha WR250 dirt bike review.