It is not quicker to drive to the MK. because the buses pull up right at the turnstiles. If you drive, you have to park at the MK lot, take a tram to the TTC, get on the monorail or ferry and head over to the turnstiles.
At AK, even if you get a close spot, you are about as far from the entrance as the buses are. you might save a moment or two in time, but it’s not a lot of difference. I would say that’s about even.
At EC, you might be in a close parking spot, in which case you will save time over the bus route. But you might also have a spot at the end of the earth, and you will hate the hike past the bus stop and over hill and dale to your car.
At MGM, it’s like AK. Even-steven, I would say, because the trams run smoothly and quickly.
Pop has its own buses and does not share with other resorts, I believe. The buses in general provide the best door-to-door service. However, if you do decide to drive. there are trams that run in the lots to take people from the entrance through the lots.