You'll find a lot of people who feel strongly each way and both sides usually present a pretty valid argument. I will say—at the end of the day it depends on your family's eating habits/style and preferences.
We almost always purchase the
DDP, however, I'm able to see both sides. Here's how the DDP works for
us:
1) We have the Disney Visa card. With the Disney Visa, it allows you to finance your trip at 0% APR for 6 months.
NOW - I don't recommend this to everyone. We're very strict and stringent with paying our credit card bills. Paying for a $7-$10k trip (Deluxe resort during Christmastime) is much easier over 6 months than in one gigantic payment. We're an older family of four (my parents, me (28), my sister (33)) so we split each monthly payment. We usually knock it off in 3-4 months, but having that leeway is nice. So, being able to throw it all on one card and pay off our entire trip in one go works for us and is an added benefit, rather than paying for the hotel and then bringing cash with us/charging more while we're there. PLUS, we get points toward a Disney Gift Card with our CC. We exclusively use our Disney CC for the trip and throughout the year, then have about $500 of spending reward money while at Disney.
Alternative: Many would argue to just put away a little money each month for the 6 months leading up to your trip. Also doable.
2) We like not having to carry as much money and worry about the sticker shock. We went without the DDP for our Easter trip. We only did 1 ADR and ate exclusively at Quick Service locations and Flower and Garden. We loaded up gift cards for Flower & Garden and paid OOP for our quick service and one Table Service ADR. We were new AP holders, so we received the 20% discount (usually 10%, but 20 for the 45th Anny). The downfall here was that we were left toward the last day or two with money on our gift cards. I know you could argue that we can "save them for our next trip" and/or use them elsewhere, but we felt compelled to finish them off. So while we saved money, we didn't actually "save money" because we wound up trying to finish off our gift cards with snacks and souvenirs. The AP discount helped—but the value of going OOP was greatly affected by Flower and Garden. We could have easily used the snacks on $6-$8 items around F&G and used Quick Service credits for three $8-items at locations where we all wanted something different. We'll be doing this at Food & Wine and I'll report back how it works for us.
Alternative: Like I said, you can load up a gift card. This gives you a spending threshold. I recommended this to my cousins who are going with us for the first time. Load up $300 and you'll only spend $300. Otherwise you run the risk of sticker shock by charging everything. You can also simply budget and only bring the cash you wanna spend—I call this the casino tactic. Last, if you want the convenience of the meal plan, simply charge everything to your room. Scan your MagicBand and it'll go back to your room.
3) My family eats A LOT. I personally eat pretty healthy year-round, but at Disney I put on a few pounds. I think nonbelievers never quite understand why we go year-after-year and sometimes multiple times a year. It's not just about the rides, characters and parks—it's about the food! We can easily polish off a meal and dessert, and the 2018 plan is even more attractive to us. I always add up the receipts and damage after the trip. I've been trying to sell my family on going sans DDP for years and trying to find efficiencies to allow us to go more often. I did it with the APs this year. However, we always either break even, or lose value on the DDP by ~$100-$200. For us, the ease of having the DDP overrides the value lost.
4) It depends on when you go. We usually go for Christmas. Major holidays are excluded from the AP Discount and Tables in Wonderland. We only eat at Signature restaurants on Christmas and NYE, so the money we spend on those dates would override the savings we see on other days.
Alternative: Many would argue that the Signatures are not worth it on the DDP. TRUE, but again, it's how you eat. We find value during our other meals, like expensive quick services (WPE, BOG) and buffets/Family Style places. Which leads me to our next:
5) The value is out there. I'll touch on the alternative first: many say they don't want to spend their trip ordering the most expensive item to make it "worth it." I can agree and that's a valid argument. Fortunately, we prefer the more expensive counter services like WPE, BOG... and we actually really enjoy the buffets (and absolutely get our money's worth!)
6) To counter point #5, though, a pizza at WPE (I think it runs about $15) can easily be split between two people.
So, it really depends. Does your family eat a lot? Get the DDP. I won't argue efficiency or ease, as you can get that with paying OOP on the Magic Band or with a gift card, but for us it just works. It gives it an "all inclusive" feel.