Watch the Aprilia
Had several friends with the 5.5 and the 4.5 and all of them had engine issues.
SUPPOSEDLY that was fixed with the '08 (help me out TYE) and newer, but I'd still be really weary
Also...note that the 640/690 KTMS are GREAT and all, but they ARE heavy. And weight makes a HUGE difference when you're on a motard.
If I could lose 60 pounds, I'd be sick stoopid fast!