I don't really know much about The Auburn, but at some point in its history this became the unofficial hangout for all people theatrical. Any given night you can walk in on a passionate poetry reading, an early workshop of a place or a singer making their way through open mic night.
It's unique in its atmosphere, especially in a very corporate feeling downtown. If the the Core was a high school, the Auburn would be the where all the theatre-nerds hang out. That's probably because there are about five or six different theatres within a two-block radius of it.
Anytime I've gone it has always been a really nice place to hang out. Sometimes I know everyone there and sometimes I don't. Just like theatre, you never really know what you are going to get and that's just fine by me.