DOH is worth a stop over if you are flying Qatar Airways and have access to the premium terminal, flying business or better first !. I would spend at leat 5 hours there alone.

Other than that I'd say, pass - Bahrain and Dubai are much more interesting.

Most of the interesting stuff in Qatar can only be done during the day - i.e a tour outside the city - I did one that passed by the major us base. Huge! and of course the natural gas fields that go on, as far as the eye can see.