Ok, I may be a bit rusty... returning to this after a ~6 month haitus!
As has been mentioned, the only way to know
for sure is to do the math. It varies widely from family to family based on eating habits, desired locations, family make up, and all that jazz. (Throw in the free dining plan promotions and you also throw in resort rate discounts into the mix!)
A few key things to consider for
DDP (
Disney Dining Plan) are:
- Does your family typically dine in a manner that's suggested of the plan? Basically, does your planned eating stuff already resemble the structure of the plan (1QS, 1TS per day*)?
- Are you looking to dine in the way the entitlements are structured? E.g. Are you interested in an entree, dessert, and soft drink at every meal? Or would you rather have an appetizer as an entree, drink water, and skip dessert?
- Would you be more likely to order from the top third of the menu (price-wise) than the bottom third? (For example, I don't eat chicken or fish or any of that, and prefer some sort of beef or steak, so for me this works, since I'm already slanted in that direction.)
- Are you looking to spend the majority of your TS meals at dinners rather than lunches (and especially breakfasts, although a few of the character breakfasts are "ok" from a cost to value perspective)?
- Are you willing to sit down ahead of time and plan out where you want to be at a given time? (This may take some thought!) Are you then willing to stick to that plan to make sure you're not missing out on any of the plans?
- Are you planning (or desiring) to spend most of the snack credits on items of ~$3.50 or more in value?
(There are additional considerations for the DxDDP (Deluxe Disney Dining Plan) as well, including the amount of courses, signature restaurants, and time it takes for that many TS meals)
If most of those are yes (well, except the rather having an app as a meal, water, and no dessert that is

), then it
should work out for you. It can still work if you prefer to share some, or whatnot, but it will require deeper planning. I still echo the "do the math" mantra that many have suggested though, as this is the best way to truly see the savings or loss accrued by the plan.
Additionally, while this doesn't pertain so much to the OP's case, if you are bringing someone along and don't want to bother with figuring out who got what, so long as most of the above are true for the group, it should work out, and that added bonus of no haggling is a good thing

. (Or, you're with someone who normally would order cheap and you want them to order what they want.)
*Technically, since all the plans are done by reservation nights, this should say "per night", but that ends up sounding awkward. And since it's just in the general sense, it can stay because I said so!
As a side note, we have previously mathematically proven that any of the plans can be a savings (even over what Disney advertises). In the same breath, we have also proven that they may be a loss. The difference between saving well and losing out is planning and picking what's right for your own traveling party.
As another side note, I am currently doing my own math, as I very well may be heading back this year, even though I swore to myself that I'd take a year off ><