I interviewed on campus (which I would recommend). It seems that most people get interviewed by adcom, but for some reason (I hope it's not a bad signed), I was interviewed by a second year student. The interview itself went really well - my interviewer was nice and very talkative. I felt like I had a good opportunity to learn about what she liked/didn't like about Johnson while she learned about me. It certainly felt more "conversational" than my other interviews at Tuck and Fuqua; although, I would still describe those interviews as "conversational" compared to a typical job interview.
Word of advice for those of you heading to Ithaca soon: if you're like me and from the west coast or a similar climate, bring warm clothes. It was around 28 degrees Fahrenheit when I was there ("unseasonably cold" for November, according to some people I talked to)