Well, finished the main story of Arkham City (I did only do a few of the side missions, but those were tedious anyway having to hunt after phones and other crap across the map). I'm pretty disappointed overall. Batman gets a few cool new gadgets, but combat gets boring quickly since it's just the same old from Arkham Asylum. Catwoman is fun to play, but she's just in for 30 minutes and a short epilogue. Collecting riddles is boring as well, and it doesn't really make sense hunting after them considering how the story pans out.
The story starts interesting, but completely falls apart at the end, and it feels like Rocksteady shoehorned in pretty much every Batman villain out there just to get a cool boss fight (who come down to either just punching through a mob of mooks or beating down a behemoth, or both). Only good thing I can say is that at least Rocksteady had some guts with the way they treated some characters (and I'm still kind of interested what Rocksteady will do in a sequel).
All in all, not sure what all the fuzz was about the game. It would've been much better if the game had more missions with Catwoman, and even Robin + Nightwing.