This cruise was a year ago, but thought I'd add my 2 cents anyway :)
I took this cruise by myself with my oldest son. I only have a few complaints, and I'll make them brief. First, I'm a single mom & was actually looking forward to the "singles party" that never happened. (It was in the Carnival Capers, & I was in the club at the specified time, but it never happened) Second, the shows were great but could do without the girls yelling the word (and I can't even begin to spell it) "Wooooooo" every 5 seconds. THAT took away from a great performance. Third, due to a problem with a sister ship, ours had to anchor out and tender us in to Cozumel. This caused us to arrive later than originally scheduled, and Carnival did NOT add time to our stop to make up for it.
Those minor things aside, we had a wonderful time. We booked the excursion that took us to the Mayan Ruins of Tulum through Carnival's website, I'd like to know what their upcharge is for these excursions!! Because we were late getting into Cozumel, this excursion took up all of our time in port. This kept me from spending too much time shopping, so I shouldn't complain haha! Words can't describe the Mayan Ruins, or the poscard-like scenery of the Caribbean. It was absolutely beautiful.