Our last trip down in Jan was our 1st time renting a car, and we loved. Didn't use the buses once. No waiting for buses, no lines, no standing room only once on them, no carrying sleeping children, no folding strollers, carrying packages. Oh, it was terrific. Plus we got to listen to the radio!!!
Getting around was a breeze. Studied a map before we left so I'd have some idea where things were. Leaving the parks at night was no biggie. We're never ones to get into the mad dash out. Just take our time, and by the time we get to the car, parking lots pretty emptied out.
And... we were able to go to the grocery store, which saved us a ton of $$. Stocked up on waters, breakfast foods, snacks. Plus, going to the offsite soveneir stores was great, things were much cheaper. with a family of 5 that kind of stuff can really add up. Eating off site was less too, although honestly we didn't do that too much.