Car arrived well before agreed time - definitely took the stress away in terms of getting to the airport.
No problem with the pick up from the hotel, driver arrived on time and the journey was very comfortable just be ready to accept the Chicago traffic. Only moan would be for the driver to be a bit more friendly apart from greeting us at the hotel never said another word...
When I called to confirm a pickup I was told the company no longer did business with the provider. I called Viator and in five minutes received a call from a new provider who did an outstanding job of keeping us informed of traffic delays--in fact, our original pickup car was stuck in traffic and I received a call from the dispatcher telling me another car was being sent so I would not be late. I was very impressed with the provider as well as Viator.