Having travelled many times from the airport to PDC and then the ferry to Cozumel, I knew my elderly parents would have trouble so I booked transportation through Best Day (also uses the name of CancunFirst). They were supposed to pickup the folks at the airport, get them down to the ferry by wheelchair or bicycle, meet them at the ferry, get them to the street and put them in a cab to their hotel. They did pick them up, but then dumped them at the taxi stand in PDC, a considerable distance for two elderly people with luggage. Nobody met them on the other side. Coming back was the same but worse, they crammed 10 people into their "private transportation". I personally spoke to the representative at Best Day and was assured the old folks would be looked after. You will get exactly the same service from any of the taxis at the airport at 1/2 the cost so don't use Best Day.