I own both KTM and Kawasaki, and both have been incredibly reliable.
Actually my KTM has probably been one of the most trouble free dirt bikes I have ever owned. Of course I never skimp on maintenance either.
So far this little KDX 200 has been good to us too, but we really haven't put that many hours on it just yet. It sure is a fun bike to ride!
I know most people have a brand of choice and that's cool. I guess I'm just a dirt bike junkie, and love to ride any of them really.