The car service is definately better. No waiting in lines to get on a bus, if you have younger children, carseats can be provided, you have a live driver who can give you a bunch of tips and stop for water, brew or other things before you board the ship, no waiting for the bus to fill when you disembark, walk outside to the gates, at the port, and your car service will pick you up immediately. Car service is direct transportation from the luggage carousels to unloading at the ship, with bus transportation you need to set aside 1/2 to 1 hour waiting and boarding the bus before you get going, not so with car service. The best thing is the price!
Disney charges $69.00 per person round trip. Five passengers in your group will cost you $345.00 on the Disney bus. Car service runs anywhere between $180.00 to $240.00, or more for the Limos, for up to 10 passengers. Of course you have to call around and talk with the different companies to get your ride and to set up your rates. There are many excellent car service companies that will provide with the service you cannot get from Disney at a cheaper price.