The DDE card is good for approx 13 months after you order it. And the it expires from purchase date, not initial usage, like an AP works.
There are many places it is good, even food courts.
Other places it does not count towards a discount, your AP might. (Fulton's, as an example) But that discount is normally only 10%. I think House of Blues might be 20% with AP.
Between the two you are covered fairly well on meal discounts.
We have a tendency to not eat at WDW counter service (only when we "have" to) due to no discount at counter, but 20% discount at sit down.
The sit down meals are by far better than counter.
Sit down meals cost more, obviously. But sometimes that cost is worth it when you look at the counter choices! (MGM as a good example.)
Counter service is one thing Universal does better than Disney. Better choices, better food, more often, and
AAA and AP discounts.
