I sat down with the menus from the Internet and selected restaurants that we wanted to eat at. Then I calculated the cost of all the meals we would eat using credits, picking food that my family would typically eat. I used $3 as an average price for eat snack credit and added in the cost of 4 resort drink mugs. I was trying to see if it made sense to do the plan or just pay as we went. I even left dessert out at a few restaurants. I would save about $300 on the plan. I think if you have kids under age 9 you save more than if your kids are on the adult plan. My kids also want to do character meals which we have 3 picked out for our next trip. Those are expensive. Don't use counter service credits for breakfast though.
Some people love the plan, others not so much. See if it works for your family but I wouldn't pick dining choices just to get the most out of the plan. I have read on the boards that is one reason some people are opposed to it. Happy dining!