Aparna:
The advantages of the
Disney Dining Plan do not lie in just cost-savings. The ability to budget and save for a significant part of your vacation in advance as well as the convenience of paying with only your Magic Band without worrying about the awkwardness of who is paying when the check comes to the table can also make it worth choosing. Its downside with a 6-day trip, however, can be the amount of food as it offers A LOT. Your plan to use two table-service credits for a Signature Dining Experience like
Cinderella's Royal Table would offset this concern.
If you are only considering the financial advantages, it may be beneficial because of the ages of your children. The cost of the dining plan for children pays for itself when you book character dining. Also, if you plan to use the refillable mug at your resort for say, milk, for cereal in your room for breakfast and multiple refills during the day, especially if you're hanging out at the pool or returning early in the evening, it's worth it.
There is an excellent cost-comparison and analysis of the Disney Dining Plan at www.touringplans.com. It echoes my thought that the dining plan makes financial sense when you have multiple children in your traveling party.
Wishing y'all a magical vacation!
Whitney