Bonus unique experience: see Zingerman's praised for its low prices.
More seriously, not all small cities are created equal. Ann Arbor has a lot going on intellectually and culturally that even a lot of other college towns do not, because it draws in visitors from the Detroit suburbs.
Oh, and I once went from sitting at the desk in my office at the university to sitting in a chair at my gate at DTW in 45 minutes. Not bad (though it usually takes a bit longer).