Congrats on getting into two excellent schools! Brent did an awesome job discussing Loyola. I'll try to offer some info on UIC (I'm an M2 here, so take what I say regarding the clinical years with a grain of salt).
1) I think Brent was absolutely right regarding surrounding yourself with people you enjoy being around and the impact it has on your development as a physician. I absolutely love all my classmates -- everyone works hard to make sure that everyone is learning/understanding everything. We share study guides, resources we come across, take time to explain things to classmates who might be struggling with a concept, etc. Plus, we have a pretty good social life -- this is more difficult at the moment because of the rate at which material is thrown at us, but a lot of us have become close friends and spend a lot of time together outside of class.
2) Curriculum-wise -- UIC has been working on improving their pre-clinical curriculum over these past couple of years. It's been shifting toward less and less time spent in pure lectures. With that being said, I have to disagree a bit with Brent in that I really don't think the pre-clinical curriculum of the school you attend matters (as long as it's not mandatory attendance!). Most people will have to spend a lot of time outside of class learning and retaining the material, whether they attend class or not. Plus, you'll see in many schools that as time goes by, even the most hardcore class-goers stop going to class and start streaming lectures at ~1.5x. It's just more time-efficient. As long as whichever school you attend records lectures, I don't think you should worry at all about how long an average day of lectures is like.
3) Cost -- both schools are expensive, unfortunately. Nothing else I can really say. It's up to you to decide whether that $30k difference matters to you or not. As with Loyola, the tuition at UIC is likely to increase slightly over your 4 years.
4) Clinical training -- of all the things at UIC, this was the primary reason why I decided to attend here. The hospitals here (UIH, the VA, Stroger, and countless others) and the patient population we see provide an absolutely incredible opportunity to get a diverse clinical education. Even as an M1 last year, I saw things ranging from bread-and-butter stuff to conditions that have only been documented a few times ever. Still remember the clinical presentation of that to this day.
There's a strong emphasis on early clinical training here at UIC. I know that every school says this (and I can't comment on other schools), but we get really good opportunities here. Last year, with my preceptor, I was given around 30 minutes to get an H&P from every patient by myself first, then I'd come out and present/discuss my findings with the attending, then she would have some teaching points (asking me what I think is going on, explaining reasoning, what findings to look for and why, etc), and finally, we'd both go in together to see the patient. Even got to occasionally write my notes in the EMR for the attending to sign off on. It was amazing and I cannot quantify how much I learned! And that's just from M1 year! As an M2, my preceptor currently expects me to function as an M3 when I'm in the clinic -- doing H&Ps, writing SOAP notes, reading up on patients, etc. We also have this thing, called Practicum, during M2 year -- they're basically mini-rotations where we get an entire week at a time (3 times total, over the course of the year) to practice seeing patients in the hospital. No classes or anything during this. It's entirely clinical. It's a wonderful opportunity to improve taking H&Ps, presenting your findings, etc. And all the attendings I've had so far have been very good teachers who spend a surprising amount of time (at least, I was surprised -- I thought they would be too busy!) helping you develop your clinical reasoning, forming differentials, etc.
All my current M3 friends are absolutely loving their rotations and raving about the amount of autonomy they get and how much they're learning. When I was deciding on medical schools, the most important thing to me was that I get really, really good clinical training. Pre-clinical education is pretty much the same at every medical school in the US. No matter where you attend, you'll learn the same basic science material. It's really the clinical years (and research opportunities) that set schools apart. UIC has a well-known reputation for producing excellent clinicians and it has a lot to do with our hospital system and the patient population we treat. So, it was the biggest reason why I decided to attend here and I absolutely love it here so far!
5) Research -- There are quite a few research opportunities here at UIC in practically every specialty. Be proactive and you'll likely find a project you're interested in and in the specialty you're interested in. There are also summer research fellowships offered to medical students here, so you'll be covered for funding, etc. Both basic science and clinical research opportunities are abundant.
6) Residency matching -- I can't really comment on this, since I'm just an M2, but my understanding is that we tend to have very good match lists, with people matching into every specialty and at big name academic centers. Attending UIC won't hold you back.
Anyways, I hope that offers a little bit of insight into UIC. Again, congrats on getting into these schools. Ultimately, go with the place you want to attend. I personally don't think the $30k difference is significant enough. Both are great schools and you can't go wrong with either. Best of luck!