Hi,
I interviewed at both Emory and Michigan. Before I give a description (straight from my own post-interview logbook), I want to tell you all my possible biases.
1. I am a lifelong southerner and love warm weather.
2. I am a fan of big cities.
That said, I prefered Emory simply because of the weather, the location, and the "newness" of the facilities. After the Woodruff grant, Emory started building like crazy, and it really shows in how nice the campus is. I also think Atlanta is a fantastic city, and the presence of the CDC and various other health organization is a real boon.
I also liked UM a great deal. Ann Arbor is a fantastic city. But its freaking cold. Surprisingly, the cost of living in Ann Arbor is similar/slightly higher than Atlanta, which is sorta surprising.
The students at both schools are top notch, and you will notice a definite regionality preference in terms of admissions. Both are great schools, but the weather and location made me more inclined towards Emory. Of course, the decision was made easier for me after the adcoms handed down THEIR decision.