Personally I would go to the KCU interview to get a feel for different top programs. I wouldn't go to CCOM unless you like hemhorraging money... That tuition turns me off if you don't absolutely have to go there
CCOM is a solid school, but this was a huge negative imo, and this is coming from someone who grew up very close to that school. In addition, it is not IN Chicago, it's about 40 minutes away. Close enough where you can go downtown for rotations or for a day on the weekend, but far enough that would make trying to commute downtown not worth your time.
I agree with others though, put your deposit down and go to at least 1 other interview so you have something to compare to. I also know the curriculum at DMU and KCU are very different, so one may seem like a much better fit for your specific learning style.
In terms of locations, Kansas City is a medium sized city, about half a million people. So you get all of the things you would out of a 'little big city' like sports, a decent selection of restaurants/nightlife, some solid concerts, and a decent variety. Des Moines is a little over 200k people, so while it's a 'city' it will definitely be more limited in terms of the things previously mentioned. It's still pretty nice, didn't really have the feeling of a major metro to me. CCOM is in Downer's Grove, which is a suburb of Chicago. It's not that close to the city, but there is still a lot to do in the area and like stated earlier, is close enough to Chicago (by car or train) to easily go downtown for a day. Even considering all this, remember you're going to be in med school, so while you will have some downtime to explore and have fun, you will have far, far less time than you have likely ever had before. So these things should be more of a secondary thought.