I have used it to book transportation to/from airports when I had colleagues traveling with me, and was pleased with the service. Worked well in Seoul, Beijing, and Singapore. In Seoul it did take a little searching for the Hyatt sign that said that all pax with pre-booked limo rides needed to head to the Hertz counter. In Beijing it was terrific as there was a Hyatt rep at the gate to meet us upon deplaning and to escort us all the way through immigration and to the car. I am sure that we could have found our way on our own, but the extra added touch was welcomed.

I would say that if you are traveling with several people the pre-booked transportation is a decent option; traveling alone it is probably overpriced.