This was our first cruise. We took the kids age 1.5 and 2.5.
Embarkation was tough. The kids were hot, tired, and they peed through their diapers. The line was long and they both melted down before we got to check-in. RCCL came and pulled us (with screaming kids) to the front of the line. We originally booked a junior suite but we were upgraded to a grand suite for free (I never found out why, nor did I ask).
We decided to spend the extra $$ for a big cabin since the kids are too young for the children's programs we needed a big room for babysitting. I really enjoyed the space of the room. It had a large bathroom with tub, bar, king bed and couch that pulled out as a bed. The kids slept on the couch. If they were older they would have been really unhappy, that thing was a piece of junk and very uncomfortable. As it worked out they are small and light and slept fine. The room had a DVD player and a great Bose sound system that came in handy. The trip was great overall and we would do it again. The room upgrade allowed us use of the concierge which was awesome. There is a private concierge lounge that has a free happy hour 5-8:30pm each day. He took care of getting all our show tickets and got us in some excursions that were 'full'.
A quick review of some useful info;
Belize is a dump. I heard the cave tubing was good but we didn't go. We took a tour (privately), what poverty!!
In Costa Maya, went snorkeling. Booked on our own when we arrived. Very laid back, ate the best guacamole I ever had at a beach restaurant in the fishing village (take a taxi to the village)
Cozumel - Jumped in a scuba trip last minute through the ship. Fantastic diving.
Caymen - Booked private tour of Stingray City with Captain Marvin's. RCCL said we couldn't bring kids under 5 on excursions. In reality the trip operators were very kid friendly. I recommend booking privately whenever possible. This is a must see, the highlight of the whole trip. Brought the kids, they did great.
Each port was better than the one before. Our suite attendant was not great. The attendant across the hall got more stuff for us than our own attendant (we tipped accordingly). The dining staff was amazing. They helped with the kids a great deal. Our kids were terrible in the dining room. The assistant waiter entertained the kids almost non stop so we could eat (we tipped accordingly). He called after we gave him the tip and was very thankful and said God bless you 20-30 times. Overall the food was OK. I suppose about as good as mass production could get. Desserts were excellent. Only gained a couple of pounds. If anyone worries about bringing small children, don't worry; bring them. They had a lot of fun, babysitting was reasonable. I'm glad they came with us.