I just returned from a RC Cruise to Bermuda with my 2 year old son. Anyone traveling with a child under 3 I would NOT recommend RC. There is nothing to do on the ship. They have playgroups for 45 minutes a day where 15 toddlers can fight over 10 toys. The pool (even the kids pool) is off limits for kids in diapers (yes even swimmies and yes they did kick us out). I was very disappointed in RC. Last year when my son was 1 we took Carnival which was 100% better. They had a dedicated kid pool (where kids in diapers were okay) and a whole play room that had hundreds of toys that was open 2 hours a day. We had a much better experience with Carinval.
I am sure others had different experiences than I did, but I wanted to share my two cents.