I found an app called Mouse savers that lists all the discounts. It shows AP, Disney Visa, TIW and DVC. They list all resorts and parks. It's been very helpful when I'm deciding on a meal last minute.
For us, one of the advantages of the AP is buying the TIW card. Depends on how/what you eat though. If you do a fair amount of TS or Lounge eating, and drink alcohol, the TIW card can pay off quickly.