Saw it today. It didn't do anything for me. It was a well made movie, there wasn't anything glaringly ridiculous, I just didn't find scary. It seems to be getting pretty good word of mouth out there, so I guess there are people that are feeling it, but it just didn't get under my skin or bother me the way, say Insidious did.
There was one scene where I did jump, but split-second shocks don't necessarily make a movie scary. Not with the tricks directors have at their disposal like sound design and clever editing. A truly scary movie will have you pinned to your seat once it gets rolling, or checking the house when you come home.
It's rated R but this is the kind of film that would have been PG-13 in the early 80s. There's no gore, or vicious on-screen murders like Sinister. It's just the exposition scenes and images of bodies hanging from trees is probably what tipped it to R.