Cruised with a group of 6 friends/family. Because I consider Carnival cheap and cheerful, I had realistic expectations. There's lots of fun to be had, plenty of activities (good cruise director and staff), and while the ship does hold more people than it probably should, it is a big ship, so one can find peace if you know where to look.
We did not dine in the MDR but booked specialty dining every night. Jiji was the absolute winner. In addition to Carnival, I've cruised on RCI, NCL, Cunard and Windstar, and Jiji is the best food I've had at sea. The steakhouse was very good; the Italian restaurant very good as well. We dined at Jiji twice -- just amazing. Do not miss it.
Many reviewers remark on the crowds, but if you do your homework you'll know how to avoid them. One of the best tips I learned from other reviews was taking your tray from the Marketplace and walking to the back through the Havana Bar. Plenty of seating, plus beautiful views. Re breakfast -- you can bypass the Marketplace all together, go straight to the Havana Bar, and you'll find the omelette station as well as beverages. The Marketplace food was fine -- simple and good, and healthy choices as well.
We stayed in the Captain's Suite 9128 which was a perfect gathering place for our group. The balcony cannot be beat: 180° views and a great deal of privacy. While I understand Carnival is not in the luxury business, if they sell a luxury suite at a luxury price (5k), they need to deliver. Upon arriving I let the steward know the fridge wasn't working and his response made it clear that he was already aware -- and it would not be fixed (it wasn't). (That the fridge was also dirty just made it more sad.) The carpet was unclean here and there, one of the bathroom drains emitted the distinct smell of cat litter (I fixed that myself with shampoo), cheap bathroom amenities (this suite should have Elemis products), we had to request robes and ice -- things like that. Again, not a luxury cruise line, but I paid well and expected better. Up your game, Carnival.