I'm one of the few people who actually loved SH4. As mentioned above, it wasn't originally a SH game. If you look at it on it's own, without trying to make it live up to SH2 it's actually really good. If I remember right, the story, when you understood the subtleties, made it incredibly personal. I also loved the 'possession' taking place in your room.
On the flip-side though.... making people go through levels repeatedly during a single playthrough has never and will never be a good idea!