I am an avid cruiser and I had sailed on virtually all major cruse lines including Costa before I took my Dec29-Jan8 Caribbean cruise on Costa Atlantica.
The good: like all other cruise lines, Costa follows its itinerary, the rooms/bars/restaurants/shows are OK compared to the other mainstream cruise lines.
The bad: they have been absolutely disorganized, careless about customers and have messed up things we could have not even imagined.