I loved this but I'm a total sucker for the classic "aging exorcist fights a demon and trains a protege" style of exorcism movie, which is nearly all of them. Say what you want about Crowe, but he's a top-notch actor and he nails the role, same for a mostly solid supporting cast, especially the main boy who was possessed. Nothing too mind-blowing in this yarn but the special effects were fun and I was satisfied with the ending.
I might have to read some of this dude's books and I'm not even Catholic.