If you're looking for what the better value is, then people are generally right that in a moderate, you'll likely save more money with the dining plan with more people in the room. Four people in a two queen bed set-up on the dining plan likely comes out way on top as compared to the room-only discount. Three is borderline, but probably still the better savings option.
That being said, you also have to factor in your dining preferences and habits when embarking on a dining plan option. It's rarely ever a consideration for my wife and me since we don't have children, so it's never more than just the two of us. For the sake of argument, though, were we to map out even the deluxe plan for our trip, we would still be discouraged by the rigidity of it. I've said it before on such threads, but the dining plan often offers a baffling combination of too much and not enough. More specifically, it offers too much food -- we like to split appetizers or desserts, very rarely do we want both, sometimes we even order all appetizers and eschew the entrees, and the dining plan doesn't really lend itself to that sort of meal -- and not enough choice. We like to eat at signatures a lot, we don't care for buffets or character meals and we like our alcoholic beverages, all of which make a dining plan option hard to justify.
Just wanted to throw that out there. If the meal layout of the dining plan looks like it will work for your party and the savings would be greater than a room-only discount, I think it's a no-brainer. But it's important to keep in mind how the dining plan will impact your normal, comfortable touring style along with the savings consideration.
