As far as excursions are concerned, I would forego booking them through the ship and doing them at the ports of call on your own. I suggest this ONLY IF you are comfortable not having things planned out ahead of time. Obviously not everyone is OK with this strategy but if you want to save money and are comfortable negotiating with the tour operators on the docks at the various ports of call you will be able to do the same activities that are offered on the ship at a much better price.
Down side items I would like to share with your are the deck lounge chairs on the ship. Let me tell you though this is not Carnival's fault but the rudeness of the other passengers on the ship. Carnival asks everyone not to "reserve" lounge chairs and states that if you are not using your chair for over 30 minutes someone may remove your items to allow other guests access to the lounges. It was amazing that EVERY morning all of the lounge chairs were taken and sadly to point out taken by someone's sandal or book. There were many people looking for lounges but unfortunately they were "reserved". The other down side was the supper club. The four of us had dinner in the supper club on New Years Eve. The food was good, the service was strange. I say this because we all felt that our servers were robots. There was no interaction, they served us and presented the food and they went through the motions. We all felt that we had better service in the main dining room every night. In the main dining room not once did I have to ask for my water glass to be refilled. My glass was often filled even before I put it back down on the table after taking a drink. In the supper club, all four of our water glasses sat empty until I had to ask, and then they were never refilled again. . It was not like the club was crowded or over booked. Strange very strange
Let me wrap up by saying that with the economy being in the dumps, Carnival realizes that Customer Service and Satisfaction are keys to their success. You will be pleased with this ship and her crew.