I liked PiT: there are interesting puzzles, the atmosphere is great, the babies are funny and charming, there's even a nice little twist at the end of the game.
But the game... how should I say it? doesn't have a strong hook that kept me playing long enough. And for a few moments it's even a bit... boring. And probably having played the top three before (SS, BiS and DT - which is my favorite) made me see all the best that the franchise had to offer a long time ago, and PiT ended up in this weird limbo.