For every trip we have taken, I have fretted about losing without doing the DDP. So to that end, I always take my end of trip statement and add up all the dining charges. Every popcorn, Mickey Bar, beverage, etc. Not having previously considered the fact that the KTTW Charges includes the tip, I can say that at least for us, we certainly win paying OOP, but utilizing the KTTW. Not being able to remember which charges included beers or a Lucky Leprechaun at R & C, I know some drinks went into that total also.
We are usually starving when we arrive, so an appetizer (no longer on plan) is what we order, we are rare dessert eaters, especially at a CS. We never get dessert there, so with the DP it would be a take back to the room food, but I don't care to lug it around the park either. DD 12 is a Disney Adult, but rarely eats like one. DH or DD 17 and I often share an entree and get and extra side. We eat everything we could possibly want, but all of the walking and rides makes full bellies not as enjoyable. All that said, we might dine TS on only 3 of our 7 days and I am not including Dinner Shows since I would never use credits for them. (We enjoy TS, but only occasionally as we really dislike too much structure in our plan.)
I overanalyze the DP every trip, and while I have already made a full slate of ressies in case FD comes out for our early January trip, I will not choose it unless we do not get a good PIN. If the PIN and FD have nearly equal values, we will take the % off. (The Free Dining option has
never been there for our previous Holiday Trip times!)
I think it is like the Value/Moderate/Deluxe issue, you need to decide what it is worth to you. Convenience? Pre-Paid and therefore budgeted? Maximum value? Morethan you would pay OOP? Of course there are lots of right answers from all the PPs because in general, whatever each of us does works for us.