I really liked the first one, I'm not sure why it "sucked" if judged on its own merits -- but a lot of it is what you bring to the viewing. I grew up in a 150-year old house in the country right next to a 250-year-old church, and my room looked out over the ancient graveyard with some stones so old the names were unreadable by that point. I'm not sure whether the full moon or the new moons were the worst: Full moons, you could see light spilling across the cemetary with the long shadows of the tombstones leaving rents in the ground, but in the new moons, since I lived in the country, it was very very black and NOTHING could be seen.
I can be hypersensitive to stimuli, and I have a very good imagination, so some nights outside walking the dog late, I'd be fine; other nights, I'd be creeped out and dash the 50 yards back to the house as if something were chasing me. And in the house itself, I often walked through it alone in the dark, and I would get freaked out near the attic door or being upstairs when everyone else was downstairs, or with all the typical creaks, settlings, and rustlings that occurred in a house like that. The house wasn't doing things that were particularly abnormal; but my mind couldn't find anything to hold onto to clarify any weird stuff I did hear.
The movie was that way for me. The first viewing, I had no idea what was going to happen, and so it creeped me out -- my mind was in hyperdrive, waiting for things to happen, and so even minor things made my skin crawl. I'm sorry, maybe a door slamming shut in a film is no big deal because you know it's a film and it's just a stupid door; but if you think something could be out there in the dark, and you're in bed, and the door suddenly slams shut with no breeze... and then you hear thudding and banging in the house that shouldn't be happening.... well, hell, I'd be scared.
So when I watched it again last night... still creeped me out a bit enough that I hated going downstairs at midnight by myself to make sure all the lights were off and the doors locked... but not as bad as the first time.
I don't invest a lot of expectations in sequels, though.