First, the good stuff. The coach house is neat and cute, and very efficiently designed. Modern kitchen, all the appliances work, fold-out sofa bed is comfy. We even arrived to a bottle of cabernet, which was an unexpected and delightful touch! You'll find a nice Italian restaurant just 200 feet from the front door, as well as a number of sports bars, cafes, etc. The West Loop scene is a short lift away, as is the Racine blue line station.
As with most coach houses in Chicago, there's a significant temperature difference between upstairs and downstairs that can't be adjusted by the central heating system. The walls are quite thin. The Airbnb is very much run as a business (though the owners are in the endearing habit of calling the locks, lights, guidebooks, etc. "theirs"), which means that anything you need will be delivered by an Uber turndown service. The service delivers to the front door and not to the coach house, so you should make sure to call the driver and give him instructions about how to get round to the back (it's through a different street).
Mimi kept in excellent communication with us throughout, but there were some small issues both with check-in and check-out. The passcode to the door was wrong, even though we'd confirmed it the night before, but we managed to get in by calling a concierge service that the owners use. We'd also arranged and paid for an extra half day's stay (check out 3:30pm), but at 11am that day, the cleaner let herself in (there's no way to prevent anyone with the code from opening the door), walked in on my mother using the bathroom, and proceeded to start cleaning, despite our attempts to tell her about her mistake! We received no acknowledgement from Mimi afterwards, but the cleaner did eventually leave. Overall, good stay, cozy home, might come back again.