I stayed here with my step-daughter (she's an adult) in January and we had an allover good experience with the hotel - we actually did Priceline and ended up at Regal Sun and we were worried but once there, we realized how blessed we truly were. The room was spacious as well. We picked up some groceries and used the fridge in the room to help us keep costs down.
The Shuttle we took was on time and bus drivers were very nice, although I'm sorry I must say we took the car the remainder of the week as we found it more convenient to drive (I have an Annual pass so parking is free). I can't comment on the accessibility component but I can comment on the proximity to Downtown Disney, which is where we spent a number of evenings. The Regal Sun is VERY close to DTD (basically from the lobby, you go across the driveway and then cross the street and you're there.)