I've only interviewed at both schools, so I can't give you insider information. But at least for me, I liked Michigan significantly more. I would guess that your quality of life for the first 2 years will be better at Michigan. For one, Michigan is P/F for the first 2 years, while Pitt has at least some kind of grading, either honors, or honors + high pass. Also, Pitt has a lot of small group activities that are required, like PBL, forcing you to roll out of bed at the early hours and get to class. At Michigan, few if any classes are required, and all the lectures are posted online. And the flex-time quizzes are another nice bonus that should make life and studying manageable.
In terms of clinical training, Michigan boasts that they're one of the top ranked schools by residency directors. Outside of that, I can't really tell you much, other than you're more than likely to get a top notch education at either school. Plus if you're planning on going into something like IM, you'll be overprepared if anything by either school. You were probably aware of most if not all of these things, so sorry if I wasn't too much help.