We are here now, and not doing the DDP, we have done it in the past. there are 4 of us, 2 adults/2 'kids' (6 & 10) so my daughter would have been charged adult price. We have been keeping track, after I predicted that it would be cheaper for us to pay oop... we leave tomorrow and are at about 400 less than it would cost for us to do DDP.
That said, we are not dessert eaters and didn't do snacks every day, we had some snacks in our hotel and stuff but not more than twice at the parks... We also did not order the most expensive thing on the menu. My total also includes my husband getting about 2 beers with most table service meals.
We ate at:
Shutters, Big River Brewery, Le Chefs in France, Le Cellier, Whispering Canyon, Crystal Palace for our table service and a bunch of counter service. My dd ordered off the kid menu about half of the time and adult the other half.
I think after this I would never do Dining again. I'm shocked at how much we saved. There is a website where you can download an excel file that will help you do the math for this..I can't remember what it is right now, but I can check when I get home!