I just interviewed at U of Colorado, so I'll give you my impression.
The most impressive thing about the place is the brand new medical center. It is now located in Aurora for the past year and a half. That doesn't get you too far in terms of training, but the residents have a very nice place to go to work every day, which is important, in my opinion.
The residents there are very happy. That being said, there is definitely a subculture there. It is more of a west coast vibe, and everyone is very outdoors oriented. Which can be good, but I think it's important to see if you fit in with the subculture at each program, and each program has one.
Fellowship match lists are good. So, my opinion here may differ from others. I take a different approach to analyzing the fellowship match lists. I don't know if you are thinking about doing a fellowship after residency, but I believe Colorado would set you up for any of them very well. That being said, it's not the best place for cardiology. Now, and here's where I differ, some will say that because it's not the best for cardiology that is some marker of the internal medicine strength. I think you should evaluate fellowship possibilities withing the context of what you are thinking of doing. All that aside, the strengths are definitely pulm/CC and nephrology. However, I met residents going into all fields.
Now the internal medicine training is very good. However, they are very spread out covering five hospitals. The strength in this is that they get great diversity and exposure to private, county, university, and VA settings. The downside to this is the logistics. You can imagine driving may be a pain. Rarely will you drive from one to another within a day; however, at some point you will live far from one or two of these, so some months will have a lot of driving from home to work and back. Now, who knows what this will look like in a year when you are applying and interviewing. There was talk of removing one of the private hospitals.
As as side note, they emphasize hospitalist training with a separate track. This is pretty unique and cutting edge in my opinion.
**edit: they take around 48 categorical and 10 prelim**
I can't blame you for wanting to move to Denver. It's an awesome city.
To me, this program is just as strong as many of the "top tier" or whatever programs out there. I think it's really underrated and quite the dark horse. I say this because residents are genuinely happy and have any career opportunity from primary care to hospitalist to fellowship, at their fingertips. Really though, this is all about personal fit and individualized training. So pick the program that fits you as an individual.
I hope this helped a bit. If you have any questions about the program feel free to pm me.