Great breakdown Rob562.
As others have mentioned, a lot will depend on how much you eat, and how you eat Princess Ariel.
That did not sound right whem I read it in my head :lookaroun
Anyway, FYI, DDE is also valid at water parks CS areas, and at the food court at POFQ (since there's no full service restaurant onsite). I'm assuming once the full service eateries open up at AK, DDE won't be valid there either.
Pros of DDE are you don't have to feel compelled to order an appetizer and an entree and a dessert to "get your money's worth." You don't have to worry about, if you use your table credit service for breakfast, you can't use it for dinner. You get 20% off restaurants that'll cost you 2 TS credits, like Cali Grill or CRT. If you like all or most of your meals to be TS, go nuts. And, very important to some, especially with what they charge, alcohol is included in the discount.
Pros of Dining Plan are it includes CS restaurants that DDE does not, which benefit lots of people who want to get back to touring. It simplifies many of the costs associated with the vacation. Tip is included in TS meals. And if you're thoughtful about where you eat and when you use it, it can sanve you a considerable amount of money.
Big questions would be - 1: Do you like to drink with meals when possible, even just a glass of wine? Do you have the appetite that warrants appetizer entree, side dish(es) AND dessert? Or do you tend to eat less, or maybe split appetizers or desserts with your partner or family? And would you rather have more table service meals? Answering those question, IMHO, helps determine whether or not MYW Dining or DDE is the better value for you.