I think it's hard to compare food to WDW, because those a restaurants compared to cruise ship food. But compared to
DCL....
- I think the buffet is better on DCL (I've been on the Dream twice). They had some higher quality items, like sushi, crab legs, and shrimp. (The sushi was cheap and fairly low quality, but was sushi nonetheless). The rest of the "standard" food was pretty comparable. We don't usually eat in the windjammer on Royal's ships, opting instead to eat at other locations.
- royal's main dining room has some lovely options for lunch on sea days. In addition to the lunch menu (which is pretty good), they have the tutto salad. You get to pick your lettuce and a variety of toppings, and the chef tosses it in your choice of dressing. It's very yummy!
- I also enjoy the main dining room for breakfast. You can eat off the menu, but have the option of picking items from a small buffet instead. It's less crowded than the windjammer and you don't have to search for a table.
- in terms of "quick service" options, Royal wins in my book for variety (on the larger ships at least), while DCL wins for convenience and kid-friendly. Flo's Cafe on the Dream is great for kids, and convenient for various activities. But Royal ships have a variety of pizza, sandwich, and other options as well. They're just scattered throughout the ships.
- I thought the food in the main dining room was comparable on both ships. DH likes Royal better. To each their own.