Have used this service at the Intercontinental many times and love it. Covered parking. Very frequent comfortable luxury shuttles to the L and airport every 15 minutes. Easy process and very courteous staff. Also, you walk right by the very nice hotel restrooms when you come off the elevator.
Most helpful critical review
If I am paying to park my car in the garage, I should not have to take a cab to make my plane on time because during peak times the shuttle only runs every 30 minutes which is quite ridiculous.