I'm not back yet, flight's tomorrow night (Sunday night). I took a bus up from new york because I was there for Columbia. i recommend it (Mega Bus, Bolt Bus would also work). i stayed with a student host in vanderbilt hall. Interviewers were very relaxed and conversational. One student and one faculty, but some ppl have two faculty. The saturday interview session was very compressed so the interviews were all in the same building. we didn't have to trek across town to go to the interviewers offices, which is what you normally have to do.
After the interviews, 2 other interviewees and i took the subway over to the undergrad campus, ate some of the best ice cream ever (at JP Licks - I highly recommend it), and walked around. Then my friend from high school who goes to the undergrad school showed me around the undergrad campus area some more, and I'm going to go and explore Boston a bit more tomorrow morning. Then, flying out sunday night.