The KTM is a work of art no doubt..The thing was put together nice and is easier to work on IMO.
I have a WR450 2007 and have ridden the 08 KTM and find that the WR has WAY more power off the bottom and into the lower mid range. However the KTM is SMOOTH, SMOOTH, SMOOTH!! WHereas the WR down right BARKS off the bottom. In some situations this is good in others not so good.
Suspension, hands down, the WR is better
Handling, not enough time spent on the KTM but it feels comparible to the WR
Other neg WR notibles: WR SUCKS to work on, stupid blue plastic, low ground clearance.
Other Pos notibles: PRICE is a steal on the WR when compared to the KTM. Legendary no break-em engine (KTM is good too). Something different then a KTM
If money were no object I'd go with a 530 and get the suspension done and plate it!!