I can totally understand most of the edits for the film, a large amount of them were to make it more family-friendly, less of a cold harsh reality and also to improve the pacing of the film and get to the action sooner. Things I think come under that reasonable would be the gyptian women accompanying them to the north, the merge of Billy Costa with the other boy included in the book and his living after the intercision, plus the change of order to have the bears fighting.
However, I also found the adaptation over diluted many elements. Apart from the removal of the key endscene, I thought overall they made Asriel a nobler character than he seemed in the book (even without the endscene). The book, to my mind, made almost everyone with exception of Lyra and the gyptians, very morally ambigious, motivations clouded by various emotional, religious and political influences. In particular the master of the university is more complex than the film presents, having chosen to bring in another Magisterium character to be the poisoner of Asriel. Mrs Coulter is perhaps the only moral ambigious character who comes across more or less the same in both mediums.
I did enjoy both, though future viewings of the film will probably be tainted by the knowledge of the deeper going on's and the ultimate devastation of intercision that is to some degree glossed over, especially with the tagged on happy ending. It will be interesting to see ifthey include a director's cut with the true ending on for the DVD releases, it being rumoured the extra scene willl at least be included. In general I prefer the book because I like the darker, more mysterious feeling it has going - the characters seems more cold and calculating, but the film representing them as more human does make sense for audience, I guess I just dislike the distortion of the book to fit with the main target audience.