We cruised on the Wonder in 1999. We had an accessible stateroom in category 5. It was wonderful. Very spacious with lots of storage. One walk-in/wheel-in closet and a huge veranda. Unlike our friends' regular stateroom which had two bathrooms, our stateroom had only one bathroom, but the bathroom was fully accessible, fully tiled and I think it would have been great for anyone who uses a shower chair. Our son was only 5 and used to taking a bath, so he was a little apprehensive about the shower. But it worked out okay. We used a bath chair for him as he has to recline. We took both his manual wheelchair (which did not fold) and his motorized wheelchair. At night, we stored one of the wheelchairs in the shower area.
There are emergency pull cords in the bathroom and near the bed. The crew responds right away when they are pulled. I learned this first hand when I knocked something down which pulled on one of the cords. Embarrassing for me, but reassuring for someone in a chair who might need assistance if s/he falls or has a medical emergency.
Our stateroom was in the stern of the boat (boat talk for in the back). We cruised in late November and the seas were a little rough on our first and last nights. None of us got seasick. We felt all the beds but the murphy bed were facing in the right direction so that when the boat pitched, it rocked us from head to foot, rather than side to side, which might have made us queasy. My father was in the murphy bed, but he had surgery for a cerebral aneurysm 9 years prior and has some balance problems as a result of the aneurysm. He said he felt great on the boat and the pitching side to side while he was sleeping did not bother him at all. Go figure!
The accessible staterooms are great because there is no step to get into them, they are a little more spacious to allow room for wheelchairs to get around. The large veranda was a great luxury.
Our only "complaint" that we had about the cruise re: accessibility, was that the elevators were so small and heavily used at first, that we were late to dinner because we had trouble getting an elevator. Our son's chairs are rather long, so we took up an entire elevator ourselves. After the initial excitement, folks began to be very courteous and some of them even got off the elevator and took the stairs when they saw that we were trying to get to another floor.
Watch out for the gangway when disembarking at the various ports. The gangway was very steep in Nassau and we had trouble holding onto our son's motorized chair going down the gangway. The chair is very heavy and we were pushing it with the motor off rather than having our son drive it down the gangway. We had to call out to two men who were coming onto the boat and were not going to wait for us to finish our descent and ask them to move aside because we could not stop the chair. Everyone had a good natured, albeit nervous laugh when we managed to avoid running into them.