I traveled to the campus, and would recommend everyone do so as well. Fellow interviewees attended class sessions and there were info sessions on interview day. 10 minutes before, a group of us were called and we went up to 1:1 rooms with our interviewers. The interviewer was very warm and had read my application in detail. She asked about my upbringing, my work experience, and my hobbies. It was more conversational than I expected.
HBS MBA Interview Questions & Report: Round 1 / Adcom / On Campus