I applied to all, interviewed at UIC, NW, Rush, Loyola. Canceled UofC due to comments by my mentors. I was too dumb to get a Cook County interview.
I personally ranked them UIC > NW > Loyola > Rush (Rush was ranked so low due to personal reasons, I needed to be elsewhere for PGY-1. I actually did like the program). I'm now at UIC.
Overall all are adequate programs in a fantastic city, and I felt comfortable at each place I interviewed. All are expected to attend the Saturday morning CCO lectures (most seem to expect attendance at 70-75% or so). Lectures run from end of September to a couple of weeks before OKAPs (March) from 9 to 11 am, giving you the summer off to enjoy the weather.
IMHO, UIC has the best research (new chair Dr. Varma is highest funded ophthalmology researcher in the country. Dr. Azar is not far behind, and yes, he still practices one day per week when he works one on one with a first year reasident), most/best home fellowships (Rush & NW also have great retina fellowships), best fellowship matches (this year: Cornea NYEEI, Cornea UIC, Glaucoma UCLA, Glaucoma UIC, Medical retina Doheny, Pediatrics ULCA. the last few years are posted in another SDN thread), didactics, and trauma exposure (the ocular trauma center for a large area). UIC doesn't have the prettiest clinics but has some of the best gadgets (Optos widefield retina photography, LenSx femtosecond laser cataract surgery at UIC and at Jesse Brown VA, confocal microscopy, amazing new wetlab being built with EyeSi simulator on the way, etc.). It is the most academic program in the city, nearly 100% go on to fellowships (that being said, a few in recent history have done comprehensive so I feel that we are prepared to do so if desired). UIC has one of the best cornea fellowships in the country, an extremely well-connected retina department with great surgical fellowship, ASPORS oculoplastics fellowship with Dr. Putterman who has invented many procedures and instruments still preferred today, strong glaucoma with Drs. Wilensky & Varma and a solid fellowship, as well as neuro & peds fellowships.
Northwestern has the best location and possibly the best facilities (although Loyola and Rush are also nice clinics). They have a few big names there with Drs. Jampol and Volpe.
Loyola and Rush seem to be more geared toward comprehensive, although people frequently do fellowships there as well. They probably have the highest cataract volume, Loyola used to have the highest in the city but I can't say for sure who does now. Rush has a fantastic retina department. The Rush setup is a bit different, with a more private practice feel and most of the faculty are part-time volunteer staff.
In terms of international experience, UIC offers 2 weeks in Brazil first year and 2 weeks in Japan second year as part of exchange programs, but this is a strictly clinical rotation and is NOT a cataract course. Northwestern residents (and maybe other programs) learn phaco in India. Not sure what other programs have a remote location for cataract electives, but UIC does not (note, we have not had the Danville, IL rotation for several years, although the website may still mention it somewhere).
I don't know much about UofC or Cook County. It seems that both give decent training but are a bit overshadowed by the strong surrounding programs.
Hope that helps a bit.