Well, they don't build junk, but they haven't exactly been responsive on this issue. Riders have been complaining about the poor sealing of the caps since early 2005. KTM took two years to admit it has a problem. Of course, they continued to produce the problem tanks during that time.
Note that this does not effect their street bike offerings, just their dirt bikes.
I still like KTMs. They offer stuff that no other manufacturer does.