To the OP... Glad you're interested in the University of Chicago! I am a resident there, and am happy to offer my input. Our program is awesome, and I couldn't be happier.
For starters... there are tons of great programs, and you need to pick the one that is best for you. And DO NOT underestimate the importance of being happy with the CITY in addition to the PROGRAM. Honestly, I think a lot of my happiness it is due to the fact that I really love the city. I have tons of friends here outside of medicine, I'm close to family, and there is soooo much to do (bars, clubs, museums, beach, sports, you name it)... If you are happy away from work, you'll be much happier AT WORK.
On a more academic note, we are kick-ass and it's just that simple. Our program has created more program directors than any other program in the country (which means good connections, and lots of respect). We are also the oldest program in chicago, we have a required flight program, and over a third of our faculty are board certified in EM/IM or EM/IM/CC which is an excellent resource.
But probably the thing that makes our program stand apart, and the reason I decided to come to UofC, was the fact that we have extremely sick patients and we are a 100% resident run program. You can not say this for the other chicago programs. I am not saying that our program is for everyone, because it's not. Many people may not like what I describe from here on out, but this is what are program is like (for better or worse... you'll have to decide).
I would say that over 50 % of our patients are completely uninsured, and most only see a doctor when they're just sick as hell, and literally can't take care of themselves at home anymore. Our hospitals is in the south side, and we have the sickest patients in chicago--hands down! Lots of patients are very complicated, often having the full boat of CHF, DM COPD, ESRD on dialysis and in multiorgan system failure when they present to us. We see tons of septic shock, acute abdomens, uncontrolled CHFers, recurrent DKA's, etc. It is not your run of the mill ER, these people are sick. We run codes almost every day (some days multiple) and many of them actually code in front of us (as opposed to the dead nursing home guy EMS brings in that they've been doing CPR on for 40 min). It is truly a great experience.
The other awesome aspect is that attendings are very hands off. We run the entire show. If a patient needs intubating, the intern does it, and if he fails, than the senior WILL do it. If the senior is unable to intubate than it's time for the senior to cric the patient (not time for the attending to step in). Attendings literally just oversee and rarely get involved beyond popping their head in the curtain, asking a few questions, then adding their 2 cents. They are NOT micromanaging or even macromanaging for that matter. You can have a patient that is having an MI, in DKA, or who has an acute abdomen, and the attending may not see him/her for 2 hours (unless you pull the attending aside to let him or her know about it b/c you've got a question about something). I think this is great b/c it let's us do all the management and allows us to get used to making the hard diagnostic and therapeutic decisions. Of course your senior resident and attending are always available as resources, and the senior is there to help you with any jams you might have weather it's a question about an X-ray finding or deciding weather to CT scan an abdomen. The bottom line is that if you feel comfortable managing the patient, then you will have full reign on it. Think carefully about this... most of the top programs I interviewed at were NOT like this! Attendings at most other high end programs micromanage and will cut the resident off and take over when things get hairy. Again, at UofC, we run the show.
Overall, we really run more like a county ER, although we're in a huge academic center. We rarely consult other services, unless it involves admitting the patient. I think this is a big change from where I went to medical school. We have admitting privileges to medicine and cardiology, so we don't have to "ask" permission to admit. When we decide to admit the patient, we call Gen Med or Cards and TELL THEM that they're getting a patient, and what the story is. There is no such thing as a cardiology or medicine consult. In fact, there is no such thing as a renal, pulm, rheum, or derm "consult" in the ER either (or I have never seen one done for that matter). All the surgical specialties are consulted, but usually only for complicated cases or possible surgical indications... but the fact that gen med and cardiology are automatic admits takes away from a lot of arguing that I watched happen at other programs. We truly keep the consulting to a minimum.
The other hospital we rotate 1/3 of our months at is Lutheran General in the northern suburbs. This hospital is very different... patients tend to be insured, educated, and knowledgable. It is a level 1 adult and pediatric trauma center. Medicine is practiced very conservatively, patients are not very complicated, generally healthy with a single system complaint, more of a typical ER. This is where we see our classic uncomplicated appendicitis and cholecystitis... as opposed to the UofC specials where it is not uncommon to have them present as a perforated appendicitis with a retrocecal abscess or cholecystitis complicated by DKA, Seizures, and A-Fib with RVR. The 2 settings definitely compliment each other and lutheran there is much more attending supervision. Every patient case is discussed thoroughly and the attendings micromanage everything and will followup on the patients entire course in the ER, so everything is discussed and learning points are made all the time. Totally, non-resident run... if we weren't there, the ER would go on with no problem. The teaching is phenomenal.
Lastly, I also interviewed at Cook County and Northwestern in chicago and I like both programs, but they are very different. Both have excellent national reputations, that's why I interviewed there. Cook has sick patients, but tends to be diluted with the frequent fliers who seek all their primary care there and get their prescription refills in the ER. Northwestern has an excellent program as well and lots of EM/IM trained attendings, but they made it very clear that 80% of the patients they see are between the ages of 18-65 and tend to be affluent/insured, so they're just not as sick as some of the other chicago hospitals. I think I would have been happy at Northwestern as well, but the University of Chicago was a much better fit for me. If you don't want to work in a county-like ER, be given lots of responsibility and autonomy, and deal with sick patients, than UofC probably isn't the program for you.
Sorry this was long... but if you have any other specific questions, fire away...
Oh yeah.... And I didn't even mention the perks of the program... the flight program, moonlighting during 1st year, and our international patient transport program where they pay us $1,000 to pick people up from all over the world (paid vacation for residents!).