I agree with
@Bjkandma - if you are thinking about renting a manual wheelchair, you, or someone in your travel party will most likely have to push your husband. Most folks who do not use a manual wheelchair in their daily lives don't make it through the first 2 hours of self-propelling at WDW, let alone a whole day. And if they manage any amount of time, their arms, shoulders and hands will all be wrecked the next day.
Disney World is flat... until you have to push a device around (any kind of device, including a stroller, walker, etc.) If your husband can drive an
ECV, that's a great idea, simply because it will be easier for everyone physically. If he can not drive an ECV, then definitely rent from Gold Mobility - their chairs will be in better shape than the rental fleet at Disney Parks, and you will have the chair available to use full time at the hotel, on the buses, etc.