SDN, read over my personal statement and browsed the school's website.
What impressed you positively?
The students there are amazingly helpful and seem really excited to have you there. They really made you feel special for having been asked to interview and you could tell they were most concernced with you figuring out whether you would be a good fit there.
What impressed you negatively?
The tour and even the process of forming tour groups lacked organization and the groups kept running into one another. My guide was talking as she went and if you weren't right next to her you could't really hear her.
What are your general comments?
Great day overall! I met some really cool people who were also there interviewing. The school can be confusing to get around, but fortunately I work in a lab there so it wasn't that bad. Leave some time for finding things would be my main advice - and don't be nervous, just be yourself.