While you youngsters under 10 is the best time to take them to the character meals if you decide on the DDP, these meals are expensive, but can be really a great way to meet and greet favorite characters while enjoying a meal. Once the children are all 10 the cost of the plan rises and the value is diminished.
I would look at the menus as well as the experiences, decide if you want to dedicate the time to TS dining, and then cost it out.
We really got the value becuase we took the kids to Akershus breakfast, Chef Mickey dinner, Fantasmic Dining Package, etc.
We also all went to BOG breakfast and ordered a full meals for all of us. Thats an expensive meal, but the girls were able to visit the Castle, and eat. They have HUGE appetites! LOL! For us it was a great use of a CS credit.
You could also take them to BOG dinner, which is one TS credit.
I always tell folks to be very honest with how they will tour and dine. Make sure you know if you will want snacks, and if the kids all like their own dessert. Do you order coffee or soft beverages with your dinner when you dine out?
WE learned the expensive way that for us, if my DH accompanies us, the DxDDP is the way to go, and have since upgraded on some trips. I underestimated the number of TS meals he would want as well as the appetizers he ordered for the family.
This can work the other way though. It can be possible to overestimate what you all will want on vacation, so I always think it is best to spend some real time planning, knowing how you vacation.
Book your meals as soon as your window opens, you can add the plan anytime or upgrade from QS to DDP if you see the need. You can cancel the TS meals, but you cannot always get them back should you decide to add them if you decide to book the regular DDP.