SDN, reddit, practiced questions with advisor and friends.
What impressed you positively?
I liked the info sessions before the interview where they told us about the curriculum structure and rotation sites. The interview was overall pretty laidback.
What impressed you negatively?
N/A
What did you wish you had known ahead of time?
They might flip your answers around on you, so make sure you can discuss why you made the decisions you made.
What are your general comments?
Overall very straightforward interview. Usually a faculty member and a M3 or M4. The last 5 minutes are for you to ask them questions so make sure to have some ready.