we went on one this time last year... it's fun.... I recommend not to book any excursions... trust me, most of them, you can go there and do for half the price, or just hang out at different places... we booked excursions at every port and we were running non-stop and didn't really get to see everything that we wanted to.
we did Carnival which seemed to be a good mix in between families and couples.
Also, There are hidden fees in things that you do there... (IE: 20 dollars a day for gratuity)