My advice, for what it's worth...
It's nice to have some sit-down places scheduled. You can always cancel the PS if you can't make it and hit a counter-service place, but they are there to help you structure your day. Plus, if you are on the dining plan, you will get more for your money at sit-down places and have an overall better experience.
If you are going with that big of a group, you are also probably putting together a schedule and deciding which parks to hit on certain days. Try to find good restaurants in those locations or at nearby resorts.
For example, schedule a lunch or dinner at Liberty Tree Tavern on one of the days you are at the MK. It's in the park (convenience), fun (character dining), and good food (not fancy, but tasty). Good for both kids and adults.
At MGM, Prime Time cafe is a good choice. It's a fun experience, and the food is great...comfort food like fried chicken, meatloaf, mac and cheese...all the traditional favorite, plus you get to have fun with the performers/wait staff.
For Animal Kingdom day, no need for PS. It's all counter-service lunches (except Rainforest Cafe); my favorite is the Tusker House
Epcot has the most choices because of the World Showcase. My two favorites are Le Cellier and Rose and Crown. But, it is also nice to take the boat from the International Gateway to the Boardwalk for some place like Spoodles.
If you want a really fun, non-park night, don't miss Boma's at the AKL. Huge buffet of excellent food, lots of choices (some tame for the less adventurous), and beautiful theming. Plus, the kids can go outside and watch the animals after dinner or hear stories by the fire pit.