Our family of 9 adults just returned from our cruise on the Concordia. Costa has designed a cruise for Europeans (not English speaking.)
Although the staff were fluent, everything was geared to Italian, Spanish, French & German speakers.
The staff were great, except the Customer service desk! English was not their first language, therefore their rudeness may have been due to translation problems.
Meals were different from other cruise lines. Much more veal, pork, lamb and less beef, but that was to be expected.
If you enjoy wine or beer with your meals, definitely book the X1 package prior to your cruise. It is not advertised, so ask Costa about it. What a bargain!!
We have been on Princess, Norwegian, Celebrity, Royal Caribbean, and Cunard (11 cruises in total). The other cruiselines should take an example from Costa in their alcohol policies instead of impounding duty free and charging ridiculous prices for drinks.
Overall, a holiday is what you make it, and we had a great time. Would we go on Costa again? Most likely.