We're going later in the year with free dining, staying at a moderate so QSDP. I've crunched the numbers too and for us there is still a savings... we have to eat something like $120 in food between the 5 of us per day. I think this is doable even though I quite likely could stick to a lower budget of food... but I think what we will do is identify places where each meal has good value (e.g. higher priced entree, specialty beverage for kids, alcoholic or specialty drink for adults). As well, we are staying 6 nights but will spread the credits out over 7 days which I think is very doable. I aged up my kids since free dining doesn't cost them more, except a minor ticket price increase, and because they are good eaters who will eat more than the standard kid fare.
If we were considering whether to pay out of pocket for the QSDP it would have been $217 per night assuming I didn't age up my kids, and $275 per night if I did age up the younger two. I definitely don't see value there.
I'm hoping to keep a log of what we eat and what the prices would have been, as there isn't much chatter on the QSDP - maybe because of the lack of value for money spent out of pocket.