This was our 3rd cruise on board a Carnival ship and while this line is not my favorite, it is great if you are traveling with a teenager. We went on a school break and our son found plenty to do--the teen club is well run and the youth staff member assigned to that group did a great job.
That being said, I would not go on a Carnival ship this large again. My son's bed was not made up on the first night and we had to wait 45 minutes for someone to come and do this. I tried but did not have the necessary bed linens.
We waited 45 minutes to get to our table in the dining room on the first night--there is not a large staging area and it becomes very claustrophobic. Once in, we were somewhat disappointed that we (family of 3) were at a table for 4--usually we like to sit with others as it is a great way to meet people. Actually, most of the dining room was made up of smaller tables so I am guessing this may be due to other cruisers preference? Our waitress was trying but seemed very frazzled trying to service 5 tables of 4. The service improved as the cruise went on--perhaps because most nights all of her tables were not filled.