Late reply, but I'm totally agreeing with dazedandbemused. I also had to make the decision between Davis and Austin, and it was a close race in everything "important" but the people totally sold Austin for me. Everyone on the visit was so welcoming and happy to get to know me, and it hasn't changed the semester & a half I've been here. It's actually kinda surprising how supportive everyone is, when I sit down and think about it. I'm genuinely friends with grad students both within and without my cohort. I can't stress enough how great this community is (to sound like a broken record).
And definitely, definitely go to Barbarella's. At least once.
Don't stress too much about finding a place to live. It's definitely doable, roommate or not, and the further you go out from campus the easier it is to find cheaper housing. Buses are free with a UT ID, so if you don't mind a bit of a commute, it can be extremely affordable. I'm splitting an $800 rent on a 2-bedroom up north, and my bus commute is no more than 30-40 minutes at worst. Granted, it's a terrible complex and we're moving, but the point remains, look outside of neighborhoods immediately surrounding campus. North of 51st, I think, is going to be your best bet. At least in my experience.