The only thing I was really upset about was the romance (oh, and Evey betraying V to the bishop. What the hell?). Otherwise, I loved it. The other changes could be attributed to an overall updating and modernization of the story; the book had a very nostalgic, almost 1920s feel to it, and I don't think that would have worked on the big screen. Updating it and making it look and feel modern made sense. The spirit of the story remained intact, so I was very pleased.