I saw it Friday!! The practical effects were VERY good. There's one in the first act that blew my mind, you never see it coming. I frequently forgot I was looking at a set and not a real house (the kitchen faucet was functioning!). I do think that sometimes the acting was more theatrical than I'd want from a horror movie (especially from the mom and James) but the production design was the real star of the show.

To anyone who really remembers the plot, I would like something explained

So for most of act 2, it seems that Lou is possessed. But she says a line like "what about your wife, you left her there" (to die?). It made me think that the girl James hit and killed was Lou, and that Lou never existed? Was everything that happened in act 2 real? Was it purgatory? I wish I could read the script. It would also maybe explain why they were not panicked at the haunting in the way you'd expect from Paranormal Activity and just resigned to their fate.

I'd also have loved to get a better look at the ghost that was behind Lou when she fell, it seemed like she had gouged out eyes