Yeah, I am doing DDP for the 1st time for this Epcot 25th anniv trip. I doubt I will ever do it again. As someone mentioned, I wouldn't normally buy an appetizer or dessert, and I normally have two meals a day, both table service. Remember also that DDP is for the number of NIGHTS you are staying, NOT the number of days. So if you are there literally, for example, 6 nights and 7 full days, then you're SOL on the 7th day. Disney counts on most people flying in late / flying out early so that you don't need that day. But I always tend to maximize my WDW time.
So why did I do it then? Just to try it out and see how it works out in practice. Plus I didn't renew my AP this year since I won't be going back until Nov next year. With the task of maximization of TS / QS / Snack points though, I'm pretty sure I'll stick to DDE.
Considering the DVC discount we get on AP's and the relatively marginal cost of DDE (20% off basically all restaurants plus alcohol), the DDE is both more convenient for me and, I suspect, more cost effective over the life on my AP.