Been on a few Carnival ships. Nothing fancy about the ship itself, not luxurious, but hits the nail on the head where it counts. Great food, entertainment, multiple musicians throughout the ship, and at sea brewery was kinda cool. People sometimes write off Carnival as a cheaper ship but I think they are more fun than most others.
Pros:
Good food. Buffet and dinners are typical but the new Burger Bar and BBQ Joint were pretty good. Carnival also does a lobster night which none of the other cruises I know of do.