I would never do deluxe dining; because, to me it's not economically reasonable. If you use your 2 credits for signature dining than you really don't get three meals, only two. If you go with three meals then you are taking away a great amount of time from enjoying the parks. I think this is crucial considering the dollars involved with park tickets. I don't want an appetizer with every meal or dessert, either.
I'm always satisfied doing two meals a day. If you think you'll be hungry than go for an all you can eat restaurant and fill up on your table service meal with buffet. I'll do an appetizer out of pocket if I want one and I'm still money ahead on the regular dining plan. There's plenty of wiggle room on cost to do out of pocket compared to getting deluxe dining.
Now, if you are willing to do split resort stays then I could see doing a few days on deluxe DP or even the platinum plan. The main reason would be that you could use your credits on your check out day; since, you are not really leaving Disney, only changing resorts.
Everyone needs to number crunch to see if it's worthwhile for your situation. To date, it has not appealed to me.
I can't justify it. I don't even find it convenient to have it paid up ahead of time which many like the convenience of that aspect. It's not convenient to me to spend more than I need to.
