I won't write up a whole review, but this was an absolutely amazing movie, one of the best (If not 'the') I've ever seen.
Bod makes a god point with the symbolism. It did lose its subtlety, although I still think it was handled well. It didn't seem forced or anything, and the dialogue remained solid.
However, I thought Harvey's fall from grace was believable, or as believable as Two-Face could ever be. He wasn't particularly evil or psychotic (Motivated by revenge, if anything), he just gave up all his hope to chance. And considering what happened to him, and the way the Joker gets into his mind, it seemed quite plausible.
Ledger's performance was absolutely insane. One of the best antagonists I've ever seen hit the big screen. Definitely Oscar-worthy.
EDIT: @ Above
I've always liked Bale's Batman voice, but you're definitely not alone in its criticism.
