My father is trying to sell his TT-R 250 and get either a WR450 or XR400 to convert to dual sport. This bike will mostly be used off-road, with occasional trips around town. Are there any reliability issues with the WR450? Will the bike need the top end rebuilt every 50 hours like a MotoX bike? I know the XR400s are bulletproof, but we both agree that the WR is a nicer bike.