I really think that there are some wonderful dining experiences at WDW and the dining plan makes it easier/cheaper to get to experience some of those. Your kids being under 3 is a big plus because they can eat free from buffets so that is a savings right there.
However, if you feel that you would be spending less than $80 (the approximate cost for you and DH) a day to feed your family, then the DDP isn't a smart choice for you. Since the DDP is required for your entire stay, you will be "stuck" with a certain number of TS/CS meals. If you only want to do a few TS meals, you could still pay OOP to experience some of the neat places to eat and spend less than the cost of the DDP. You really need to calculate how many TS meals you would do (and how much those would be with tax & tip - because those are included with DDP) and add in your other costs (CS meals and snacks) to see if the plan would be worth it for you.
We really enjoy the dining plan but it isn't for everyone.