My company's headquarters are just outside Detroit. One positive is the city was logistically built and spread out to house 2-3 million people but yet only has 900k within city limits meaning traffic isn't that bad for a "big city." I love when my Detroit counterparts drive into Chicago and are late to the meetings because of traffic they didn't expect. But hey if we go to Detroit it'll be a cheap 2 day vacation versus the money I shell out to go south and watch the Hawkeyes get dismantled.
Also not a huge part of downtown, but Greek town near the casinos is nice with some good restaurants.
I spent four years of my life living in the Detroit area; so it's near and dear to my heart. I too wouldn't mind a bowl game there either, though I know most Hawk fans are rooting for something far bigger in nature than that.
I used to work in downtown Detroit very close to the Eastern Market. The casinos have all been built downtown since I lived there. I've now been moved away from Detroit for over 20 years.