This was our first time on Carnival, previously sailing on Royal Caribbean and we were anxious to see what the differences (if any) were. First and foremost I would caution anyone thinking of booking air thru Carnival we arrived at port less than 30 minutes prior to sailing and I would never cut it that close again. Next time we will book our own air (Southwest no bags fee) and most likely arrive the day before sailing.
The boarding and disembarking went very smooth and our transfers went off without a hitch. (my sister did miss the boat in Miami, not the fault of Carnival, and she was able to board in Cozumel)
We were pleasantly surprised with the size of our cabin in fact my sister and her daughters shared a nearby cabin and they had plenty of room even with three in the room. The bath was larger than on RCI and overall we were very pleased with the room.