I'll bite. Note that I've just recently been accepted to med school myself but I have close friends that go to both schools.
I've not heard the best things about the environment at UK. From what I've been told it is a more competitive and stress filled atmosphere. However, I personally love lexington and think it's a great city to live in. Cinci has just done a lot of renovations relatively recently and the school is pretty sweet. The people I know really enjoy it and seem to have as much fun as you can while in med school.
But those are pretty small things and I can't speak to much more. I'd go to wherever you have in state tuition. Unless you're from NKY where you get both.