This was an RCI package cruise and the worst way to ever travel (bye bye RCI) because it was either a balcony on Costa/MSC or an interior room on the bigger names, like Royal. We decided to try Costa and it will be the last time.
First, Costa likes to play the "we're separate entities" game when dealing between the host desk and tours. No one is responsible to the passenger but the department that doesn't belong to Costa, and they all belong to Costa!
The food is horrible and what other reviewers say about closing down the buffet early is correct. I lost weight on this cruise..and while that is a surprise, it's only because the food was mostly disgusting.
Balcony -- avoid deck 5 -- you're right over the life boats and there are bright lights shining all night long that will impede your ocean view. Our particular cabin had a slow drain in the shower and when they finally plunged it, enough hair to cover a hairpiece was recovered. Later I saw a man waiting in the forever-host-desk line yelling "when will they clear the sewage backing up into our room?!!" Clearly Costa doesn't maintain their rooms.