I read the book and didn't like it. Saw the film tonight and thought it was incredibly well done. Dark, twisted, fantastic soundtrack by Trent Reznor.
The ending had small changes but largely the same. I didn't like the ending in the book but I thought the film did it well. I liked that it didn't conclude in a sweet little package.
I know some criticism of the book was that none of the characters wee likeable, but so what? I don't have to like characters to enjoy a book. I liked that no one was likeable.
DH thought the film was great; Great story, well done. He hadn't read the book.