I went to Chicago undergrad, so my experience is mostly with the school overall. There is a good LGBT community, and the atmosphere is very positive and laid-back. From people I know who went to the law school, I got the strong impression that it was the same.
Note: Chicago's conservative reputation primarily comes from its economics department, and the fact that several prominent members of the faculty are very associated with approaching legal questions with an economic methodology. I don't think the school is particularly socially conservative compared to its peers.