Warning: "heresy" coming!
I agree that unless your eating patterns track what you get on the DP you're better off using TIW...BUT!!!
I got the TIW card this year--and discovered as I went from restaurant to restaurant (over the course of 3 trips) that my AP and/or my Disney Visa got me essentially the same discount, pretty much all the time.
Didn't track it "scientifically" but did ask at each restaurant which of my possible discounts was best (TIW, Disney Visa, AP or
DVC)...in all but about 2 places, AP and/or Disney Visa were as good as TIW; one place didn't take TIW at all and at no place was the DVC discount as good as the TIW, Disney Visa or AP...
So, if you have an AP and a Disney Visa, you can probably save most, if not all, of what you'd save w/the TIW card...
I know I'm not going to buy it again next year...
Of course, if you don't use APs and don't have a Disney Visa, this is irrelevant!
Have fun w/whatever you decide...