So let me just start out by saying that this is strictly a review based on my opinion. As an "all things horror" fan, I feel like I should voice my thoughts on this particular film for those who may have not seen it just yet. I won't give any serious spoilers, promise!
As we all probably know by now, this movie was based on actual events and the book written by retired NYPD Detective Ralph Sarchie. Following his retirement, Sarchie took on the task of becoming a demonologist and working with the Priest pictured in this film. I have to admit that demonologists have always fascinated me (Go Ed and Lorraine Warren!) so this fact really drew me to the movie.
In terms of fairly recent horror movies, this one didn't absolutely suck. I feel like the camera work could have been a lot better as well as a more organized story line. There was also a rather interesting nod to The Doors in this movie and I'm not sure if I can listen to "Riders on the Storm" anymore without being creeped out!
I'd have to say that out of all the possession movies I've seen, this one could be the most realistic. This movie lacks many of the "exorcism" special effects such as spewing green vomit, levitating people and objects, and spinning heads. I appreciated that aspect of this movie very much. In regards to jumps and scares, there was probably only one good one. Will you have trouble sleeping after seeing this? I don't think so. Do I recommend this movie to others? It's interesting enough so I'd say yes however, I'd wait until it comes out on DVD.