I used Tiffany last Christmas and overall was disappointed. The driver who picked me up was unaware that when I booked, I had requested a grocery stop and seemed annoyed telling me he would have gone a different route if he'd known. I double checked my reservation and it was clearly requested so he should have been upset with the dispatcher, not me. On my return, the driver arrived an hour earlier than scheduled and wanted me to leave, but we weren't ready. The cars were clean, luxurious and I loved walking off the plane directly into the waiting car that was parked in some special area. The drivers drove safely. But I didn't like feeling as though I had done something wrong on both legs of the transport when I hadn't. Of course we still tipped the required $20 each way
This last trip I took a Lyft and it was overall a better experience and less than half the cost. The only bad part was waiting outside for the ride to arrive (maybe 10 minutes?). It was not the special parking spot that private transport has access to.
eta: I am not a seasoned ride share person. It took a leap of faith for me to use a Lyft this past trip. Thats how disappointed I was with my private transport experience. Because why pay $200 round trip plus $40 in tips when the drivers make you feel bad. For reference I paid less than $100 Round trip including 20% tips for Lyft.