The ship is sharp and well laid out . . . it is actually the same ship as the Carnival Legend/Miracle twins with a bit classier decorations and fittings.
Costa out shines everyone on embarkation proceedings . . . but is in the "not ready for prime time" class for food and tours.
Food . . . well prepared but dull compared to other cruise lines such as NCL and Royal Caribbean . . . and with poor access. A 3 hour only lunch buffet . . . less than 2 hours for served breakfast . . . and no dinner or evening buffet options were very old school. You essentially eat at your assigned dinner time or starve!
Food was well prepared but with very limited choices..
Tours had to be pre-purchased and there were no refunds. Costa then mixed languages which essentially gave you half a guide. When questioned, the tour staff shrugged and essentially said "tough".