This is good advice but take what "regular" students say lightly as well since the students you talk to may have some personal problem with the school and therefore tell you the student is horrible. My point is to just be sure to judge everything for yourself and don't base it on what others say about it. Also, trust the tour guides a little bit because actually at most schools the tour guides are not being paid but are in fact volunteers. So they actually like the school and are not just telling you what you want to hear. So it's best to take what everyone says together when deciding on how you feel about the school.
Also, I really think visiting schools is important because it could help you avoud going to a school that you end up hating. Speaking on personal experience, Georgetown University was my number 1 choice, but about 5 minutes into the school's info session, I hated everything there was about that school. I left before even taking a tour.