It certainly varies by the chef. We've had some great ones. The worst was the ex british army chef who didn't salt anything saying "you can add your own salt". Um, it isn't the same. He also complained about how the crew smelled up his kitchen with their stinky soups, and spend most of his time on deck taking pictures. We never saw him again.
Breakfast is breakfast. On our itin in November the menu never changes. We'd sit down and say "oh look, french toast and classic eggs benedict" today, every day. The eggs on the buffet are horrid, but they'll make you fresh. THe coffee is much improved over previous years.
Lunch is sort of like they're phoning it is. The trip in November featured a cream soup of some sort EVERY DAY. Talk about calories!
Dinner we have no issues with. I probably send on entree back each itin and they'll happily replace it. On a longer itin you'll start to get the same menu twice, but there's still lot's to choose from. Candles has really expanded their menu, on this trip we felt like the meats have been downgraded and tended to the tough and stringy. Everything is fresh - no mixes, etc.