The qsdp is not worth it unless you are going to use all the credits for lunch and dinner, use all the snacks, plan to eat dessert with every meal, and plan to get use out of the mugs.
For the
ddp -- especially for 2012, it is not worthwhile unless you want dessert with almost every meal, and plan to use the vast majority of your adult credits for above-average priced entrees. For 2011 pricing, buffets were a good deal on adult and especially kid credits. But moving forward, it no longer appears most buffets will be a good deal with adult credits, unless buffet prices rise significantly.
And with all plans -- you must be willing to sacrifice flexibility, and eat in the way the plan is designed.
You can easily eat 2 good TS meals for $52 in 2012. Might skip dessert and soda, but eat very well.
Or for $52, get just 1 ts meal, with soda and dessert, and 1 cs meal, with soda and dessert.
Heck, you can do 2 cheap ts meals for $35.. Or get the qsdp, which includes 2 cs meals.