In May of this year,I toured the Greek Isles with my wife and 2 other couples on the Oceania Liner, Nautica. It was an extremely disappointing experience.
Except for the 2 exclusive restaurants on board, the food in all other eateries was poor to fair. The prices for wine, beer and hard alcohol were excessively high - similar to what you pay in a fancy hotel.
Service was very spotty. The higher up the wait staff positions, the less satisfying it was. The only real polite service came from the runner type, non-paid youngsters. Not all, but enough to mention, of the professional wait staff had unpleasant attitudes.