First, I have to react to all the reviews that say that this film is so medically wrong that they can't take it seriously. I just have to say that they don't know how wrong they are. I work in the ER of the largest hospital in Europe and had to cope with H1N1 flu outbreak as a "reference center" and you can't imagine how f... up the organization (at every level, from our equivalent of CDC to the hospital administrative board) is. Had H1N1 virus been the "bad guy" of this film, we'd all be minus our tongue by now. (and don't get me started on "they should use a cure, why don't they do this or that"...).
Apart from that, this is really a great film for someone who loves his scares with a brain. Of course, if you prefer stories about a bunch of teen ages who just decided to go to the woods where an serial killer offed a few people 10 years ago just for kicks, you'll get bored out of your mind by the first half hour. But if you enjoy films which don't take you by the hand from point A to point B, don't overexpose their villain, and scare you on a deep level (the one you only can reach when you KNOW these things could happen), you'll love every minute of this film.
So don't go and see it if 1)you want to see heads explode 2)you want to see some cleavage 3)you want instant action from the moment the lights go out
Go and see it if 1)you like films that are rooted in the real world 2)you like intelligent films ("Alien" is a very intelligent film) 3)you can stomach truly gross scenes
Whether you like "found footage" or not is inconsequential, this is one of the best use of the genre I've watched (better than Cloverfield, as good as Rec, wasn't very fond of Diary of the Dead).
