What was the most interesting question? pretty standard stuff, one question about having a family while in med school (I'm single so I told him it wouldn't be a problem) I was asked this too
What was the most difficult question? one interviewer really laid into me about my limited clinical experience, after I explained my schedule (lots of work) we didn't let off and talked about busier applicants I was asked this too
What impressed you positively? the campus is really nice, also the caliber of applicants there (Harvard, Stanford, etc.)