First, STL is a terrible commute from pretty much everywhere. Not a lot of flights, multiple jumpseaters fighting over flights from hubs (which are mostly on 50 and 70 seat planes...). Unless you are driving and live halfway in BMI, CMI, PIA, I'd say a commute to Chicago is hands down better than STL. On top of the commute sucking, Chicago is likely to have better trips because it is a hub. STL is more likely to have 5 AM show on the first day and 11PM arrival on the last... making your commute that much worse.

Second, if you are wanting a Chicago base, there are much better options than G7...