He is not in a wheel chair but can't stand on a bus. Going to. Poly for the monorail and boat transportation. Thought private ride would be better for him less waiting, grocery stop on the way and we would have our luggage with no waiting.
Disney's Magical Express uses motorcoaches (long distance buses with airline-style seating), not city buses. The number of passengers assigned to each Magical Express motorcoach does not exceed the number the seats.
The advantage of Magical Express over a car service is being able to skip baggage claim. Yes, you have to wait for the motorcoach to be loaded and dispatched, but, when you use the free Magical Express luggage delivery, there's no waiting for checked bags to appear at baggage claim and no shlepping them through the airport or the resort.
Experienced Magical Express users have learned to take carry-ons with anything they need the first day (Florida clothes, sunscreen, swimsuit, etc.), along with the usual things one should always put in a carry-on (fragile and valuable items, medicine).
That way, there's no need to wait for bags at the airport or at the hotel room. Because Disney pays the inbound bell services gratuity, you don't have to be in your room when the bags are delivered.
With Magical Express, there's no grocery stop, but there are other ways to get groceries and beverages, such as using a grocery service such as WeGoShop.