To answer your question about what I did not like on Royal Caribbean:
There was a group of 100 family and friends arranging in ages 5-60. A lot of them were first time cruisers BUT there were about 40 or so that had been on a carnival ship the year prior. We went on RC in Jan 2000. The ones that had been on carnival previously noticed as SOON as we walked on the ship the atomsphere and music was NOT like Carnival. I am 45 years old and I guess most that went were in that age group. We like to have fun (no staying drunk) just participates in every contest, game they have. The FUNSHIP "party" atomsphere was not near as much on the RC. The only thing the RC had that carnival did not and it was fun was the scavenger hunt (for adults) both have scavenger hunts for children. The children who had been on the carnival were disappointed NO WATER SLIDE, no 24 hour pizza, no ice cream. We stayed on the empress deck inside on both the RC and the Carnival and the rooms were smaller on the RC. We asked our room steward to remove a chair just so we could have someplace to put our luggage.The age group on the RC were much older than we were. I mean 70's and probably above. Don't get me wrong it is great that elderly people can travel and have fun and when I get that age and want the peace and quiet then I would probably consider RC over Carnival but not while I am in my 40's and have a thirteen year old. The children preferred the carnival by far. The food was good on both ships and the ports were good on both ships but actually staying on the ship we all preferred carnival. Our travel agent told us RC was a step above carnival and recommended this ship. We all thought different. We are all pretty average people who just like to have a lot going on and have fun. Participating in the games is hilarious. With a group as large as ours someone was participating in all the games. We are going on the Imagination in January
Plus for RC if you do not want the party atomsphere and you are older.
Carnivals room larger.