Emily Rose was a much better film, I think, and based on a true story, while Exorcist was quite loosely inspired by a true story, as best as I can tell.
First of all, I don’t really get the horror genre. It does not produce in me what most people enjoy. I watched them both in the dark, by myself, Katherine was in Memphis for the week. I had no trouble sleeping, no nightmares, no fear at night, etc. So, the horror just didn’t work for me.
The films were more interesting to me from a theological standpoint, although they certainly emphasized a kind of theological perspective of which I know quite little, practically. Clearly, filmmakers are rewarded for sensationalism and so I have no reason to trust the films for their fidelity to reality when it comes to working with the demonic. However, I certainly believe the demonic realm to be real . . . I’m just not sure about the way these films portray it.
I’m not sure how to recommend or discourage others from these films. They certainly might give some people nightmares, needlessly. On the other hand, I don’t see much reason to avoid them, but nor do I see great value there either. Hard to say.