I ended up buying this and I'm having a ton of fun.
It was nice that all my progress from the demo carried over to the full retail purchase too. To be honest, I've been having way more fun with this than I thought I would. I just find all the lay out and quirky Batman stuff so slick. Haven't had any problems with matchmaking.
Also, all that DLC I thought was ridiculous and lame is customisable stuff you can actually unlock anyway, they just give you the option to pay for it with MS points, which I don't really think is a bad idea.