if we can't fly in the morning of or if we are coming in a few days ahead we like to spend the night at disney. it starts the vacation out nicely. we do dtd for dinner the night before and use their transportation so its really easy. we did rent a car once and drove ourselves (not to my liking) and we have had car service several times however i like to go with their bus service.
having said that, lots of people don't like to use their service from wdw because you get to the port a bit later than you do by other forms of transportation. to me, to lose an hour on the ship or walk on board with no crowds….no comparison. but again, only my thoughts. not everyones.
have a great cruise.