I was a bit underwhelmed by the books - they were page-turners, for sure, but Pullman never seemed to quite get a grip on some of the crucial issues (for instance, "dust") and so a lot of stuff felt a bit hazy to me. That, and the writing was at times a bit clunky - yes, I'm aware they were written for children but all the same the way reviewers (especially in Britain) gushed over the books you'd think Pullman was the second coming of Joyce or something.
Having said that, the first book was a corker and was easily the best of the trio, in my opinion. I'd probably go and see the film, as the books did deal with interesting issues and Pullman, to his eternal credit, didn't shy away from making tough decisions about his characters and, by extension, his audience. If the film(s?) can keep that same attitude of treating the audience with a bit of intelligence then it could work out okay - although, by removing "all that god stuff" they're pretty much ripping the central metaphor of the book right out - it sounds rather like making a film of Moby-Dick and leaving out "all that whale stuff".
One very, very good thing about the books is that reading them gave me the impetus to go and read Milton's Paradise Lost, which is absolutely magnificent. And I'm sure I'm not the only person in the world who rushed out to read that after finishing His Dark Materials.