I don't think I screamed or anything, but the last minute or so did manage to make me jump - although how much of that was a reaction to almost everyone around me doing so or the film remains to be seen. The film felt suffocating its last thirty to twenty minutes, that's for sure.
My brother found the film so scary that he took off his glasses at one point, because he didn't want a clear image of the film as the tension got kicked up to eleven. I had to take him to Denny's for coffee and food afterwards, and I just woke up to find out he did not go to bed at all (just stayed up with the lights on and played Halo).
The film does veer a little into Hollywood shock territory near the very end, but I can't say that's a deal breaker and the business side of me says the original ending would've been divisive amongst audiences.
Also, I think the filmmakers show a remarkable amount of restraint (more likely due to restraint). There aren't a ton of cheap scares piled on each other, very little is actually shown to you and they cleverly condition you to start feeling dread at certain points - only to work that to your disadvantage.
As presented, people actually clapped at the end. There was a lot of applause.
And that's something I don't ever remember seeing at a horror film.
Here are some pictures I snapped while we waited in line for two hours. This is what the place looked like 90 minutes before the film started, in the only theater in the DC/VA/MD area playing the film (AMC Loews in Georgetown - home of The Exorcist!). Place was packed; management had to open three more screens to meet demand.
