Just returned from a 7 day Caribbean cruise on Breakaway, my first time on BA, second on NCL. Our cruise had 3,000 passengers. I was very apprehensive because of the many negative reviews I've read, but overall it was better than I expected.
The good:
The ship was beautiful and in great shape. It looked brand new.
Nice balcony cabin. Quiet location. Could sometimes hear neighbors, not sure if it's because of thin walls or because they were just loud talkers. Most of the button on the cabin safe wouldn't work, so my combination for this cruise was 4444. Bed was near the balcony door with only about 9 inches of space between then. If you have a cpap like me, bring a really long extension cord. Mine was 10-ft. and it barely reached an outlet.
Too crowded when 2 large ships are in port. Swim With The Pigs excursion was worth it.