Just off the new Breakaway- my husband is a wheelchair user and very independent==most of the ship is very accessible, be aware that you cannot access the sport deck without calling ahead ( at least 30 minutes) and asking to have someone operate the stair lift that goes to the Vibe and another one on the stairs leading to the basketball court. While we were told that the lifts are "probably" cycled every day, we never used them, since we have had terrible luck with lifts in the past. The area on deck 16 is very crowded and has clear dividers that make moving around somewhat of a challenge.
Our cabin was a wheelchair accessible one located on deck 14, very roomy , automatic door - which is very slow in closing so be prepared to have people starring into your cabin. We did have a balcony, it is double in length- but it is as narrow as all the other cabins. You could NOT get a large wheelchair, or an electric chair out on the balcony. Elevators are very crowded at times, and you must be aware of which bank of elevators you are using. Some go only as far as deck 15. Accessible bathrooms are large and single use and are located all around the ship. If you go to the cirque show, be warned that the wheelchair seating is in the premium section and there is NO accessible seating in the regular area. We hope to contact NCL and have a discussion about this.