Well here's my experience,
I've had a greater quantity and frequency of jams with semis, 80% of which being stovepipes, quick easy fix.
I've only had one revolver jam, it was a Taurus .357, the trigger stuck and failed to return forward. Ended up having to be taken to a gunsmith and something had to be polished. From what I know it runs fine now (it's not my gun).
My verdict,
Semis seem to be more prone to jams but they are usually fixable, it still may cost you when seconds count but you at least have the possibility of fixing it on the fly. If something goes awry with a revolver you better have a BUG. That said if you buy a revolver from a more trusted company, like Smith or Ruger, then you'll probably be alright.