I bought a 450EXC earlier this year. I use the bike to chase my kids around the motocross track and light riding around town. I previously owned an XR400 and the KTM is a superior in all categories engine , handling, suspension. I have added the required skid plate, Scotts steering stabilizer, hand gaurds, 50 tooth rear sprocket and installed the appropriate springs in the suspension. The factory springs are to light for a 225 lb man. I ride the bike around town very little only because of the tires and the FJR. Oh yeah, I replaced the seat with a Corbin due to tailbone problems I have. The Corbin is firm but quite a bit wider than the stock seat and works very well for me, again let me stress the importance of the proper suspension springs for the riders weight.
The bad, oil and filter changes are a little tedious due to 4 oil filters two paper and two wire mesh, also I use the recommended Motorex engine oil and it is expensive but I can live with it.
I've crashed the bike hard once and dropped it several times and have broken two rear turn signal lenses. The turn signals are designed to release upon a crash but if you hit it with your foot getting on the bike you can knock it off and the light has to be disassembled to reinstall on the bike requiring a phillips screw driver a little bit of a nuisance.
Hope this info helps out the KTM is a great bike and a ball to ride.
DB