It was a really good day -- met with a lot of faculty and most of them were real friendly and just wanted to answer questions. The only really tough interview was with the director of the MD/PhD program who went through my application with a fine-tooth comb: asked questions about every little thing in my application and things I said.
read interview feedback, went over applications, looked at school website
What impressed you positively?
How helpful and friendly the interviewers were. The day was very organized, every minute was accounted for (so much so that I had to hussle just to get a bathroom break!)
What impressed you negatively?
The day was really rushed because each interview was only about 30 minutes and I had to book it from building to building. Fortunately, secretaries showed me where to go, but others weren't as lucky and got lost and were late to interviews/meetings.
What did you wish you had known ahead of time?
bring floss! (after lunch you still have interviews)