I went to see this film in the first week it came out, to get maximum jumps with a room full of screaming people. As someone who found paranormal Activity and Insidious scary (the idea of something huge and invisible being in your house is a horrible thought!) this was a total let down, it had some scary moments but the build up didn't ever get there, to top it off the things they had her saying were just hilarious, the whole room was laughing instead of screaming when she's writhing round the table being possessed and that and she's shouting all this funny stuff- it wrecked the atmosphere.
Honestly the biggest jump this film gave me was when a dog jumped at the wall when the characters were walking past. It was interesting that they pulled religion and the Vatican into it, but it wasn't enough and the story just didn't get anywhere.
The ending could have had another scene of exorcism where they really pulled out the stops but they chose not to, the ending is actually one of the worst I've ever seen, it's like 'Oh. That's the end?'