You might want to consider checking out the Disabilities Board, there is a wealth of great info over there and they can answer all of your questions with expert answers. There is also a thread about accessible rooms.
Suzanne
The disABILITIES FAQs thread near the top of the board has a section about resorts - including a description about the 2 types of handicapped rooms.
When making a reservation for a person in wheelchair, it is really important to be clear what exactly is needed. For example, someone may be in a wheelchair for distances, but can get around in the room just fine. That person would need to request a first floor room
for medical reasons in a hotel without elevators, but would not need a handicapped room. Someone else might want a bathtub, but needs grab bars in the tub for security. They would need a handicapped room, but would not want a fully wheelchair accessible room, because those have a roll in shower.
We've stayed at all the moderates and they all have their pluses and minuses. Other than CBR, the rooms are pretty much the same, so I'd suggest looking at the other features and decor to help you decide.
PO-French Quarter is small and easy to get around, but distances might not be a problem for you because of having a wheelchair. There are elevators, but you may have to go out of your way to use them. There is a boat (wheelchair accessible that goes back and forth to DTD). The food court is small.
PO-Riverside is larger, but still pretty easy to get around. The Mansions have elevators, Alligator Bayoo does not. The food court is larger and easy to get around. The same boat goes to DTD.
CBR is the oldest moderate and has the largest rooms. None of the buildings have elevators. There are scattered beaches (for looking at, not swimming). You can't walk to any parks, but if you are at the Old Port Royale (food court) and go out in the back of that, toward the water, you can see the higher fireworks. The food court is nice. The buses can be crowded since it's a large resort, especially at the last stops.
Since you already know you aren't interested in Coronado Springs, I won't talk about it.