Haven't I seen this before? - "The Last Exorcism"

I've been seeing commercials for a new movie called "The Last Exorcism" lately and, as one would guess, it looks like a mishmash of plenty of other horror flicks. That's really nothing new as most horror movies draw largely from the ones that came before it. However, "The Last Exorcism" looks exactly like "The Exorcism of Emily Rose" in every commercial I see for it. The former movie seems to focus more on the actual exorcism in the style of "The Exorcist," whereas the latter film is more of a courtroom drama. They each try to grasp for some realism with the audience, "The Last Exorcism" presented as "found footage" or documentary style (not surprising, after the reception for "Paranormal Activity"), and "Emily Rose" presented as based on a true story. "The Last Exorcism" looks like "Emily Rose" minus the courtroom drama aspect. Aside from that? I'm not sure what new ground this new movie is breaking. I suppose these types of movies have built-in audiences and a built-in group of people who will always be terrified by exorcism-themed movies because of the basis in religion. I personally enjoyed the melding of courtroom drama and supernatural forces in "Emily Rose," but I don't know if I feel like seeing the same movie again. I also have a hard time imagining the lead's performance in "The Last Exorcism" could be nearly as strong and disturbing as Jennifer Carpenter's performance in "Emily Rose."