This is a huge improvement over the dreadful second movie in the series. In fact, this third entry seems to completely ignore the previous movie. As this is a continuation to one of the greatest horror movies of all time, it's always going to live in the shadows of the original, to the point where it's almost unfair. I think this movie has quite a lot of creepy and chilling moments and as some people may already be aware, it also contains one of the best jump scares in horror history.
Since this movie is just as much a serial killer flick than it is a possession movie, there is an opportunity here for the small group of people that do not care for the original movie to find some enjoyment this time around. I believe there is a more recent bluray release which has some sort of director's cut version, which ultimately changes a lot of the latter parts of this movie. I haven't checked it out yet, but I thought it was worth noting that this review so far pertains to the theatrical version.
The ending to this movie is not entirely unsatisfying but does feel a little a bit rushed in its execution. I believe this is because they were pressured to put an exorcism scene in the movie which is changed in the director's cut version mentioned above.