I don't think you should spend too much time studying facts and statistics about any school where you interview. I really don't think your interviewer will be impressed or even want to hear about stuff he/she knows you can get off the website or out of a book.
I would choose one aspect of the school that attracts you and be ready to discuss that. Most of the interviewers I spoke with were more interested in my questions than they were in my answers. I had at least a few questions ready for each interview, and I made sure they were not questions I could get out of my own research or from the tour of the school. If I interviewed with a MD, I asked questions about medicine, such as "How much opportunity will I have as a doctor to volunteer my medical services? Is it better to choose a specialty that suits you intellectually or emotionally? What is it about medicine that gives you the most satisfaction, or frustrates you the most?" I asked things like that, which gave the doctor an opportunity to start a discussion with me about things that interested them, and I found a way to connect with them personally. I don't know if it is the traditional way to interview, but it made for a more relaxed time.