I come from UIC college of medicine, so take my advice with a grain of salt.
I think UIC has a strong program with good clinical exposure (University hospital and nearby VA) and a strong didactic curriculum. The new chair, Dr. Zar, is a graduate from UIC college of medicine and was residency director at St. Francis for several years. He's actively involved in teaching on the wards, and attends Grand Rounds and M&M; our previous PD did not attend M&M though I think she went to GR. The program is fairly large and while there is some class/department cohesiveness there are lots of circles of friends like you would expect to see at most places with large programs. A fair amount of autonomy, as there are no private patients. Things used to be ward-based but I hear the word "firm" being tossed around these days so I'm not entirely sure if that's changed over at the University. I spent most of my time at the VA which is a great place to learn. Oftentimes frustrating, what with little to no ancillary support, but near total autonomy. Call schedule is also one of the lightest in the city, AFAIK. Q6 on the floors at the U and the VA, Q4 in the unit at both. Interns do get tapped to do both night float and sometimes ectopic call in the unit to make it Q4 (there are usually only 3 interns in the unit).
Rush, OTOH, has lots of money and lots of connections. Beyond that, I don't know much about it...