It never occurred to me to rent a car. We always fly (sounds like you are too, this time anyway), so I can't see adding the cost of a car, like PP. And with ME, we don't have to wait for our bags; sounds like you'll have a lot to wait for and wrangle with 6 people. We just get on the bus, get a cool drink in our refillable mugs at the resort, and wait for our txt saying our room is ready. I do online check-in, so we bypass the front desk, too. It's about an hour, maybe a little more, from landing to poolside, depending.
Then there's the fact that it's always me who has to figure out the route and do the driving. It's become easier with Google navigation, but with a Disney vacation, I really want to be on vacation. Oh, and I hate parking lots ( the only accident I've been in was in one on Long Island). They bring out the worst in everyone, inside our car and out! So whenever I get a glimpse of the lots from the bus on the way to a park, I think, glad it's not me.
The downside is some resorts have the very last station at the parks, and that can be a long, long way on tired feet. We usually get a seat, but they do get very crowded.