I've beaten it and have to agree with everyone else here that it's a vast improvement over the first. I liked the story and the core gameplay elements of the first game, but the pacing and repetition was just awful.

It still has a non-ending, so don't expect anything to wrap up at the end. It just produces more questions than it answers. I heard somewhere that they initially intended this as a trilogy and given the sales figures, I can't see why they wouldn't capitalize on that.