Depends....
Now wasn't that helpful??

Seriously, it really does depend on your situation. We were there in January, and stayed in the mansions. We got a room on the first floor in the inner courtyard of Magnolia Terrace. We had requested Magnolia Terrace, 1st floor, connecting room with my parents. All of our requests were met. The walk wasn't bad for us, but my parents had a tough time with it. For my family, being in that location was fine. It would not have been worth the extra money to pay to be closer (although if we were stuck in one of the far out AB rooms, I would have thought paying for preferred would be worth it). For my Dad especially, he probably would have paid anything to be in a ground floor preferred room. He walks with a cane and has pretty severe arthritis. When we booked, there were no preferred rooms available. We did see preferred become available at one point, but decided since the preferred buildings don't have elevators, we absolutely could not risk my dad not being on the ground floor. This is why we requested the mansions to begin with.