Unless there is a money tree growing in your backyard, I'd stay with medical students. Jeff apartments are right next to the library, which is where your interview will be. There are also plenty of places to grab a quick breakfast nearby. They should have sent you a list of med student email addresses with the interview invitation.
It wasn't stressful at all to stay with students. I kind of just wanted to kick back in a hotel room the night before my interview, but after I saw that all of the hotels in Center City were booked a month before my interview and the only ones anywhere near Jeff were $399/night I quickly decided to contact the med students and stay with them.
The interview day starts at 10 am, and there will be about 30 other students interviewing. You sit in a HUGE conference room in the Scott Library, and listen to fin aid, students, and the dean talk. Then, you have a student interview. First year medical students will start piling in the door around 11:30, and will whisk you away to some isolated corner where you'll spend 25 minutes talking. Then, there is a catered lunch (beware: it wasn't too good of lunch so eat a good breakfast). Then, you have a tour followed by your faculty interview. PAY ATTENTION during the tour because you're responsible for finding your interviewer and being there on time. The day wraps up with cookies and mingling with students (I felt so strange for this because I hate mingling).
I interviewed for the PSAP (Physician Shortage Area Program) with a family doctor and so I didn't get a lot of ethical questions or anything. We just talked about my background, experiences, and goals.