I'll jump in since I just came back from there... Malapascua is definitely a place worth diving at. Great diving, but so are a lot of other places. Since you're going for your Divemaster, I think (as has already been mentioned) that there are other considerations. Having been to PG also, I concur with the others here for all the reasons that they stated.
I've just posted the first installment on Moalboal and I think they would be a good choice also, better than Malapascua for some of the same reasons that PG is also better (IMHO). Busier means more and better experience for you as a Divemaster candidate.
I know it's tough... as you say there are just "to many" choices when it comes to the Philippines
