When we stay onsite we bus everywhere. I am the only one who drives on our trips to Orlando, since my car is stick and my wife has no want to learn to drive it.
When we stayed at PO it was great getting on the bus and not having to drive. It was a lifesaver the third day when I was dead on my feet from being at Epcot all day...I slept the whole bus ride back to the room. The boat ride tip to downtown disney is also a good one...it was relaxing, and beautiful to pull up to the dock with the sunset behind the ballon ride.
When we stayed at all-star sports last year and had two ambulatory grandmothers with us, it was great to have the buses. it seemed to take forever to get anywhere. But, the amount of time and patience the drivers showed, it was worth it.