The good bits: Morgan Freeman, Michael Caine, the humour over getting all the equipment together.
The bad bits: an utterly bizarre, ridiculously complicated Evil Plot (the Joker's was better in the first film), the scrappy editing for the fight sequences, the civil damage caused by the tension-free car-chase, the lack of any real role for the sole female character.
Comparing it to Miller's Year One: in the book, Gordon's role is a parallel and counterpoint to Wayne's; here, it's barely a role at all. Flas is a much nastier piece of work in the book. And in the book, it's Gordon who gets the romance, not Wayne.
But it was better than Sin City, anyway.