I must say that this being my 2nd cruise with Carnival and 2nd in my life I am not the most experienced cruiser in the world but will offer my opinion anyways. For whatever it is worth :)
We boarded in Miami and I must say that it was a much better port to load at than Fort Lauderdale. Much smoother and organized. We had no issues boarding the cruise and although we had to wait for some time to get into our room and luggage and so forth, it was no big deal to us.
We went to the buffet as soon as we boarded and I had Guys Burgers. Best burger that I have had state side! The buffet was ok, as I am not overly fussy on what I eat anyways and always found the food fresh and appealing.
Clean and well attended. Our cleaner was always friendly (though hard to understand) and we could barely turn around and our room was taken care of!
Best place to cruise out of. Nice terminal and very organized
Took the Eco park tour. Was very disappointed and eaten by misquitos! Tour guide made the trip as she was very knowledgable. Locals are very agressive in sales
Water was dirty but beach was nice and clean compound!
Excellent excursion. My wife and I had a blast. They needed more beer on the catamaran as we drank it all! Watch out for us Canadians! LOL