We did the Playa Mia beach break. It was very nice, beach was extremely clean. Had open bar with complimentary lounge chairs and waiters to bring your drinks if you wanted him to.
We enjoyed this port very much. We did a tour of the city, we did not book with Carnival, but one of the independent companies. The beach at Mahogany Bay is beautiful.
We decided not to do an excursion here. We took a shuttle to the fishing village and walked around the shops. They are very aggressive trying to get you to come into each shop as you walk by. We visited Sam's Corona Bar where they let you use lounge chairs and tables with umbrellas for free, the just ask if you purchase any food or drinks that you order from them. They also had free wi-fi that let me message home to check on my dog :)