It isn't released here until the 3rd so I've yet to play it, although I have the demo on the PS3 to play later today.
I was one of the few people that absolutely loved XIII though.
XIII-2 is getting amazing reviews for the gameplay, but pretty rough ones for storyline. I want to find out more about what happened post XIII so will be playing this regardless. They've apparently fixed a lot of shit that was wrong with XIII and it feels more like a Final Fantasy game.
Random battles, Gil from loot, towns and nonlinear dungeons.