I'll take the same approach as Stephanie:
Towards the end of my senior year, I had narrowed my college list down to three: Caltech, Hopkins, and a double major in Plan II (liberal arts honors) and BME at UT (Texas). I had actually gotten into UT and Caltech before Christmas and was fairly certain that I would go to one of those two. Before I got my decision from Hopkins, I went to visit Caltech over spring break. I took the tour, met with faculty members and talked to a bunch of random students. I really liked the atmosphere and the campus, but the fact that the school was extremely science/math oriented and that the Admissions office likens the school to "drinking from a firehose" kind of turned me away. At that point I was fairly certain I would go to UT - most of my friends were going there, it was nearly free and they had great programs in BME and Plan II.
When I got my acceptance from Hopkins via email, I kind of dismissed it - I really had no intention of going there. But since I was offered a scholarship, I decided to visit the campus for an overnight visit. Before visiting, all I thought I knew about Baltimore and Hopkins was that it wasn't a very safe place. My visit totally turned my view around. When I visited, I stayed with a current student in the dorms - I highly recommend this to anyone who can. There's really no way to get an accurate impression of student life from just taking the tour - you have to actually live it for a day to see what it's like. My hosts were pretty busy since they had a physics test the next day, but they still took time to show me around, take me to dinner etc. Plus, I got to see what the academic atmosphere at Hopkins was really like. I had "heard" how it was cutthroat and how people would literally try to do well at the expense of others, but I saw nothing of the sort. Since there was a physics test the next day, when my hosts took me to the library and through the dorms, I saw tons of study groups working together in the hours before the exam.
So in summary, try to stay overnight if you can. If you can't, try to talk to random students during lunch or something - that's the best way to get a good impression of any campus. Hopkins is definitely not for everyone, and your visit should help you figure out if it's where you want to spend the next four years.