We were in cabin 8598 in the center of the Brilliance. It is not a very large balcony cabin but very comfortable and close to the elevators. It is a quiet cabin. Once we had everything put in it's place the cabin worked quite well.
Bathroom was adequate - no problems.
We prefer being center ship near the elevators. Makes life easy to be able to return quickly to the cabin for forgotten things or to store purchases you don't want to carry around.
Balcony comfortable, on the hump, and bed very comfortable.