We used Dollar Express for our last trip in May. I don't think it was very "express" I waited and got the luggage with one son, and DH went to get the car with another. I waited for 30 minutes before he came back to help me. And then we had to check in with another desk in the parking garage. They make it sound like you will have your car in 5 minutes which is not the case. We've had a car faster taking a shuttle to Thrifty offsite. However, Dollar gave us a brand new leather seated Chrysler Pacifica with 10 miles on it. That was nice.
Hope that helps.