Read SDN, my application essays, and the Chicago Tribune.
What impressed you positively?
The attitudes of the students. Everyone really loved attending school there, especially working in the non-competitive environment fostered by the strictly pass/fail system.
What impressed you negatively?
There weren't many windows in some of the buildings - I am guessing because the view would probably not be too plesant.
What did you wish you had known ahead of time?
The faculty and doctors are very accessible during the entire med school experience. It is very much like a small undergraduate school experience.
What are your general comments?
The interview went great. Make sure that you give yourself PLENTY of time to get to the school from where ever you are in Chicago because morning traffic is horrendous. Two people were late (and not just five minutes) because of traffic, and I know that didn't make the best impression.