I just watched this on demand and I thought it was fantastic, though I wish I had access to it in HD. Excellent acting, and very suspenseful despite it moving at a snail's pace.
I loved Daniel's summary of his day after he was baptized, when he described his adventures with Goat Man. Everything he said had happened, but the way he described it made him seem completely insane.
I also liked how near the end, he sat at the girl's grave listening to the Walkman and most likely the tape we saw him find in the attic early on.
The prison stuff was also very good, like when they were cleaning out his friend's cell, and there is an overhead shot of Daniel's cell next to the cell of his friend. Also, how they went back and forth between shots of him pacing his bedroom and pacing his cell, showing the similarity of the rooms and how he was treating his bedroom as a cell.