*IF* you can treat the flights like a bus station (show up, get on whatever is leaving next) then MKEORD segments are nice. If flight loads and schedule cuts no longer make this possible, then I'd be inclined to drive it.

Trans States and SkyWest are running fewer flights on the city pair than Air Wisconsin was, so there are substantial gaps in the schedule during the course of the day.
The overall hassle factor clearing security at MKE versus ORD, and the in-garage rental car facility, is a not insignificant factor for somebody visiting from elsewhere, I think, as well. If my time is of value to me, I'd rather take my chances with the flights 9 times out of 10. And be prepared to get screwed and drive after all the 10th time