Here's the simple answer: as long as MK is not part of the trip, the fastest and most direct way is to drive yourself. ALWAYS. Note that cabs will give you equivalent drive time, and will eliminate any parking delays, but the carseat issue may require you to call and wait for a taxi that will accomodate your family, so time may work out as a wash.or slightly behind the speed of your own vehicle, while the cost of using cabs repeatedly will certainly add up to more than the cost of a rental car. The only add'l caveat is that parking at Downtown Disney can be very scarce, so you can waste time looking for a space there. For the MK, buses are fastest unless you are coming from a monorail resort, because of the issue of dealing with transferring at the TTC and the trams. When leaving the MK to go back to a resort at closing time, the fastest option usually is to walk over to the CR and take a cab from there, as the monorail system and buses are usually packed, and you may have to wait through several of them before you can board. When our kids were little and apt to fall asleep once they left the park, we often took a midday break and then planned to have and early dinner at an MK resort -- where we used valet parking for the evening and headed for the MK after dinner. Then at closing time we would just put them in their PJ's and brush their teeth at the park, then hang around Main St. taking photos or shopping while they slept in the stroller, until the crowds cleared. Then we took the monorail to the hotel, had the car brought around, and drove them back to the resort to be slipped into bed without waking them. PS: re: hopping -- if you plan to hop FROM the MK to a water park, the fastest way is to go back to your resort, pick up your car and drive to the water park. Buses between major parks are direct but don't run as often as you would probably like. It once took us 2.5 hours to get from MK to DAK via bus, counting the walk to the Monorail, the monoraili ride to the TTC, finding and waiting for the DAK bus at TTC, drive time, and then walking into DAK from that bus stop. Driving between parks has never taken us more than a total of 30 minutes. Also note that if you drive to the MK late in the day, you can usually park right up at the front of the lot near the bridge, next to the disabled spaces, because the majority of the early birds who got there before opening have left by about 5 pm.. From there, walking directly into the park only takes about 10 minutes and allows you to avoid waiting for the monorail or ferry when leaving at closing time.
I am also a bit worried about timeframes as I know nothing happens quickly when you are waiting for busses....
