My banker hubby just did these numbers yesterday and for myself, him and our DD (who will be 3), the Dining Plan is better than using our DDE last year. We don't drink, so getting alcoholic discounts isn't an option, and we don't eat counter service, so we ate very well on our 2 trips last year using DDE.
This is what we did:
1) Added up all our receipts (all table service except 2 counter service on day of check in and check out) using DDE for July (exact same dates as last year, so equal comparison for this year)
2) My DD ate free at all buffets as she was only 2, but we had to purchase for her at other restaurants - we then added in 3 additional dinners that she was asleep for in which we would have purchased her a meal
3) Estimated for snacks - the biggest thing for us is water as our DD has dehydration issues. We aren't big snack eaters so not too big of an expense for ice cream, etc.
4) We aren't big breakfast eaters at all - a bit of toast, milk, juice or fruit, so we pick up a few groceries and eat in our villa
5) Also added in DDE expense - we did very well on both trips and more than paid for our DDE card
6) We then got our grand total and divided it to make a per day/per person total (don't have that in front of me right now)
7) Grand total for 11 nights using Dining Plan: (2 adults, one child) $956.00
Basically we came out over $200.00 cheaper by using Dining Plan for this year - now the food isn't exactly equal as we ate at more table service restaurants last year as we eat table service for lunch and dinner and hardly any counter service, but when you add in appetizers, dessert and drinks (normally just drink water), it may even itself out. This year of course, we will be eating at more counter service restaurants and getting more snacks per day, so for us with a just turned 3 year old in July and 2 adults, the Dining Plan is looking like a better option not just financially, but ease of use, not having to renew DDE, tax & tip included. We are a bit worried about counter service as we have allergies and health issues, but we've eaten at so many places that we pretty much know which ones have the healthiest options for us (we don't eat hamburgers/fries hardly at all - so we like deli sandwiches, soup, etc.) We are very excited to give the Plan a try this year!
Good luck to all who are contemplating this decision. You really have to do the numbers for your family - I see lots of posts trying to convince people one way or the other, but the only way to make a proper comparison is to do your own numbers (using old receipts is the best way!)
Best of luck, Tiger