I took my time watching Twilight. I guess I was bothered by the casting most of all. Now, I'm not sure why I care because I did NOT love the books, but I did read them all, so I don't have a lot of room to complain. Neither Edward, nor Bella look like they did in my mind. I really SHOULD have a good physical picture of Edward what with all the references to his white teeth and hard, cold body... but I guess I pictured him taller, broader, better looking. I know there are girls all over who swoon at the sight of him, but I can't imagine why. He just seems sort of normal.
The book wasn't great, but it was a better read than film. If I'd not read the book I'm not sure I'd fully "get" what was even going on in the opening sequences.