I've taken their shuttles twice to Chicago from ISU and maybe 4 times from ISU to U of I. Traveling between college towns isn't bad at all; actually I'm very pleased with their service there. However, never again am I taking it to Chicago!
The first time was absolutely horrible. Granted, it was the friday most universities let out for Thanksgiving Break. But they hired an extra driver to prepare for the holiday rush who was supposed to take us to the Chicago area and connect us to our destinations. This lady was very nice and didn't have a clue as to where she was going! She kept harassing other drivers for directions and for translations from passengers when she didn't get it which resulted in me being on a bus for 6 hours instead of 3. There were 2 girls catching flights at O'Hare and they didn't make it. If you need to take this shuttle to the airport consider Amtrak and commuting through the CTA first or at least leave half a day in advance.
The other time going up to Chicago was fine but it didn't say where on the web site or the email where my pick up spot at O'Hare was going back. I called and asked but let's just say I almost missed my bus back to ISU because someone lied.