I’ve only cruised twice, and both times Royal Carib. Carnival always seemd a bit sleazy to me...
I did some work for Royal Carib’s office long ago, and they took me for a tour of the engine room on one of those.
(I don’t remember which ship it was, but it was docked there at the time.)
I couldn’t believe the size of those engines - they were massive. I was impressed by their entire operation.