Very problematic to confirm reservation, poor customer service from the people on the phone. Not there on time eventhough they had our flight itinerary and we called when we landed and again when outside and it took almost 30 minutes for the driver to arrive. The driver was professional and pleasant. Their booking service is poor.
On arrival at San Francisco airport I called regarding the transfer. They had no record of us whatsoever. After one hour and 3 phone calls, they finally sent a sedan to pick us up. The driver was great and apologized for any inconvenience caused and drove us to our hotel and gave us a commentary on SF sites as we approached the city. The car was very comfortable.
I had confirmed this transfer in January when I was in Calgary and they informed me that I would have to call when we arrived at the airport - which I did and it took over one hour to sort everything out. It was extremely stressful and tiring considering we had just come off a 13 hour flight from New Zealand. However, the driver made up for the mix-up.
Not a necessity but it was very nice. Didn't wait very long at all. It costs just a little more than a cab and you have a better ride. Be ready to tip though.