Here's my take on things... By the way, long-time reader, first-time poster. All 3 are among my top choices, so I've tried to get a good feel of each of them.
Rush - Rush is a solid school. The people I know who are in med school at Rush or are associated with it rave about it. The administration and faculty at Rush are very dedicated and are very open to helping the students. The atmosphere is very student-friendly. Lecture hours are a bit on the long side, something like 9-5. I haven't met a single student who was dissatisfied with their experience at Rush.
Illinois - A lot of the students I've talked to from the Illinois system show a lot of reservation about their school. I don't have the time right now to totally get into it, but basically in-state tuition is the biggest thing it has going for it. Student frustration in the 1st 2 years is rampant, at least at the Chicago campus. I think it has something to do with the way the system is set up. Don't get me wrong, there are many good things about Illinois med, but there's also a lot more baggage.
Loyola - Loyola has a very friendly atmosphere. I think they approach teaching medicine in a very holistic manner. The administration and faculty truly care about their students' education. I got a very good feeling from Loyola. Lecture hours are 8:30 -12:30. Small group discussions every couple days. They have one class at a time, so they'll have Cell bio for 8 weeks, then anatomy for 12 weeks...etc... Not to mention the facilities. I know that's not what one should be overly concerned with, but they are really nice.
That's all I have time for now. I actually have to get back to work. I work at Rush, coincidentally.