I just wrote a long-ass review of this, but I accidentally hit the back button and now it's all gone!!! ;-;
In summary, I said: the movie was awesome, Taylor Lautner is fucking sexy as hell, Rachelle Lefevre looked good, too, even though I didn't much care for her in the first movie. (is it me or was her hair redder in NM?) Jaime Campbell Bower looked awesome. I expected to see him, but had no clue what he'd look like. I was pleased, definitely.
I think it kept to the book pretty well, especially in the beginning. I felt that it was almost word-for-word in many places.
I can't say if it was any better or worse than Twilight, but I know I preferred this one... possibly solely because Taylor Lautner (TayLaut) runs around shirtless A LOT. I wish I could rewind time and just replay that one scene where he first takes his shirt off over and over again. I swear, the entire audience of teenage girls probably feels the same.
I definitely recommend it if you liked the book.