Sorry to say that I don't have a PS4 but have watched a few LPs of the game. It's not bad, although it didn't overly impress me. Perhaps I would appreciate it more if I could play it.
One thing that I find interesting is the lack of interaction with objects - when A Machine For Pigs was released many people were up in arms about the lack of object interaction (naturally they were comparing it to all the interaction in The Dark Descent). But with the PT Demo there is barely any interaction at all, but I have yet to see anyone complain about that.