If you're really looking for an honest answer, here's my opinion: It depends upon your expectations. We were three families who cruised last March with a total of 6 children: Ages 3, 3, 4, 4, 5 1/2 and 7 1/2. The 23-month-old child of one family was left back at home with grandparents.
All of the adults had (unrealistic, as it turned out) expectations about having adult time while children were in the childrens' clubs. That's one reason we took only children who were at least 3 and potty-trained.
All children spent some time in the clubs, but the older ones enjoyed it much more than the youngest ones did. My nearly 8-year-old son awoke every morning asking how soon he could go to the club. On the other hand, my 3-year-old daughter was not as eager to spend as much time in the clubs, although she was happy there for some of the time. And she was happier in the club than some of the other children we were with.
My expecations going in were that all children would love the clubs and the adults would have long parts of each day without children, relaxing with a book by the ocean. That did not turn out to be quite true.
So if your expectation is that it is a vacation for YOU while the children are happily occupied elsewhere, with such young children that may be an unrealistic expectation. I now view it as a vacation more for the children, and as such it was a complete success. Much of the fun for us was seeing the joy the children experienced. They loved the characters. The stateroom TVs show Disney movies, and when we were in the stateroom I allowed them to watch those movies, while I was happy to sit on the veranda. The movie theater was a big hit. The sports deck was also a positive.
One one of the days at port, the adults left the children in the program while we explored the island, then we returned later that day to pick up the children and go to the beach. It was nice to have that option. I don't know whether you can leave the little one in Flounder's Reef while you leave the ship.
Bottom line: I personally would not do it with a child too young for the program. Of the three families that went last year, we are the only ones considering going back next year (youngest will be 4). One family thinks it's too much money to spend on children so young, and that renting a beach house with a pool works as well or better. One family, the one with three children, won't go back again until the youngest child is 5.
My children are looking forward to it. My son loved doing snuba and my daughter loved Minnie Mouse and Cinderella and the other characters. I felt it was a pretty safe environment. My husband and I spent our honeymoon diving Grand Cayman years ago, and we'd like to return, and this is an easy way to go with the children. I can't think of what other, better vacation I want to take with a 4-year-old, that my husband and I will also enjoy. When she is 5 we will go skiing like we did with her brother, but for this next year we will probably go back on the
Disney cruise.
Good luck to you whatever you decide! I know there are a LOT of people who bring babies and toddlers on the cruise. I wouldn't find that fun, but we're all different!