My family of 4 children, ages 11-14 and 2 adults sailed to the Bahamas on Carnival Fantasy in December, 2011 Christmas cruise. We have sailed a half dozen times on Carnival, Princess, and Royal Caribbean. Although a relaxing cruise, we would not select again for the following main reasons:
1) The food. Breakfast and lunch were fine at the buffets. Dinner detracted from the experience. Our poor waiter was so overwhelmed by all his tables and new assistants that the service was poor. The food was surprisingly bad - even foods that are relatively easy to prepare. How can you botch a cheese cake? Answer: be too cheap to include any cheese - tasted like a bad sponge cake. On a six night cruise, 3 meals were fine and the other 3 were poor. Service was slow. Kids couldn't get refills on "bottomless" soda. Some nights hard to get refills on water or another slice of bread if the meal was delayed. Menus and food were disappointing. I'm a diabetic and have enjoyed sugar-free desserts most recently on Princess. In 6 nights I enjoyed only one dessert. We didn't starve - but we didn't really enjoy the meals. Carnival has skimped too much from the dining room budget. Major problem. Wouldn't sail again.
2) Camps. We were told our 11 year old camp is in a 9-11 year old camp. NOT TRUE. The camp is 6-11 most of the time. There is simply no way our 6th grader is going to camp with 1st graders. I looked at the camp schedule, there was really nothing he would have enjoyed anyway. In the other camp 12-14, we had 3 children. 2 passed, and 1 did everything. They all said the games were lacking, e.g. the basketball NBA video game is from 2007, there is nothing from after that on board to play. Nothing great - doesn't seem like there is any real effort.
3) There isn't much to do in the Bahamas. Freeport is basically a waste. We went to the beach on our own in Nassau (the Sheraton Hotel - $5 taxi, and $25 beach fee - both per person) and had a nice afternoon. Key West is completely overrun with tourists - a shame because when I went 20 years ago it was special.
4) Entertainment: the carnival dancers were great - when they performed (2 nights and a holiday show in 6 evenings). The other three nights there was a terrible blues singer from New Orleans, and C-rated comedians. However, the costumes and enthusiasm of the carnival dancers was wonderful on the nights they performed. [Note the theater of this old vessel has poles, and the balcony slopes very little making it hard to see from the 2nd row upward - want to get there early to watch].
Staff is nice, ship is in great shape for 20+ year old vessel - little noise or shaking. Showers are hot, nothing bit us. Only issue is with public bathrooms being dirty - but the boat is small and it is easy to get back to your room. There was also an odor in a few of the hallways. Rooms are fine (we were interior - no problems). No lines of any significance except for laser tag. Convenient port to our home in Atlanta. Charleston port is inefficient takes over an hour to get in and it is easier to take your own bags off the boat than let them remove them. Candidly, if they would fix the food, it would be fine for the money - as it is, I would spend more on airfare to cruise elsewhere. It isn't bad and you will have nice memories with your family. It just isn't special - and that's a shame because we would cruise annually out of Charleston if we enjoyed it.