I predict David C. all the way and that it won't be much of a "humdinger" as Simon expects. David A. is a good singer and all, but still quite young and lacks variety. Save a few, winning it all has been the kiss of death, though, and is something I don't really wish on either of them.

EDIT: My prediction is based solely on the merits, incidentally... my fear is that in reality David A. may still walk away with the teenybopper vote.