It depends on the group traveling. The parking at TTC for handicap is closer to the TTC entrance, but the rows are very long so you can be quite a distance. My sister was using an EVC, so she drove that, but if she had been using her rollator, she would have been too tired. If she had been using her wheelchair, I would have put my foot down and we would have taken the bus. There is a bit of a dip that would have been hard for me to push her back up.
The only reason we drove is that she has a phobia of not having transportation somewhere and we do enjoy taking the ferry to MK. We did take the bus one night and she had some trouble, but no one said anything or rushed her on the EVC.
As long as no one that would be walking has trouble with the distance, I figure it is a wash. It could be faster getting to MK via bus, if you do not stop at multiple resorts or have a long wait. If you have multiple stops or long waits, then driving could be faster.