I was in that exact same cruise, and thoroughly enjoyed it. It's all subjective, obviously. If you spend ANY time in Europe, you'll realize that they were not being rude, and that the rolls ARE indeed fresh. The food is NOT, I repeat, NOT American! It is, <gasp> ITALIAN!! C'mon people!
Some complaints are valid. Overall, though, my wife and I had a great time. The room was spacious and clean; our cabin steward and waiter were wonderful; and the ship is beautiful.
I guess you have to be a little more open-minded to enjoy a cruise on Costa.