The best advice to give is to find out what the kids want to do and then decide. I agree that RCI's Freedom OTS or Liberty OTS are good for those who are adventurous and want to rock climb, ice skate, surf, etc. However, if your kids don't want to ice skate, surf, or rock climb, then any of the Carnival ships will occupy them from wakeup to sleep time.
Research which cruise line will fit you the best based on what you and your family want out of the vacation. You should consider cost vs what they offer (activities) in your decision.
I choose Carnival because the price was right and the ship fit what we wanted to do. I don't do rock climbing walls, can't skate, and don't have a desire to surf, or don't care about "enrichment" activities--I wanted unlimited fun where I can do what I want and when.Balcony cabins are the way to go, best thing about a balcony is you can come back down to the cabin, plunk yourself on the balcony, and unwind until you feel like going to bed.