My sisters and I decided to give my mom and dad an all expense paid cruise as their Christmas gift 2012. We set to go this past December 2013. Adults only, we left the children at home. Just my mom and dad and their children and in laws. We had an awesome time on Carnival Elation. Though I have been to Cozumel a few times it was Mom and Dad's first time and they loved it. They enjoyed the tour of the island and Mayan Ruins and they enjoyed just being on the boat. I think being on a cruise with your family is just awesome. We had time to get away from each other and than Dinner time to come back with details from the day and make plans for the next day.
One negative was that the water was a little more ruff the first day or so and it made a couple people have to stay in their room, but other than that we had a great time. We look forward to doing it again in a new place but on Carnival for sure!