I chose this cruise because of the itinerary and the price--as a first time cruiser, I didn't really consider that the age of the ship may be a factor in accessibility.
My biggest issue was the bathrooms. Because it is an older ship, I suppose the bathrooms haven't been updated. Our stateroom was an OK size and had enough space to park my electric wheelchair and 3 beds. The bathroom layout was not great, I needed help to use both the toilet and the shower because of the awkward angle and the fact that the shower bench seat provided was VERY tiny (and I am a very small person!) even though I can do it myself under normal circumstances.
Elevator access was a nightmare. There were many times we waited 15+ minutes for a single elevator during peak times before deciding to just go waste time somewhere else on the deck before going back to our room.