This is one of those subjects that everyone has a thoughts or opinion on,..... so here are mine
Frist off were are you staying? if in a Value Resort the " free dinning" plan covers 2 QS and 1 snack per person per day. Moderate or above "Free Dinning" plan is 1QS , 1TS and snack per person per day, or if you are planning a lot of dinning, character or signature meals (2 TS entitlements) you can pay the cost to upgrade to Deluxe Disney Dinning Plan which is 3 TS ( and you can use them at QS sites) and 2 snacks per person per day.
Only you can decide on... what amount of food you need or restaurant you want try or want to experience while on vacation. Also you need to think about how you tour... Commando, Laid Back, everyone tours differently. Stopping for TS does take time, but it does give everyone some time to sit down, relax and regroup. For us vacation included meal times, to talking to each other, some of our best memories are at meal time.
We personally like the dinning plan, yes you are paying for it in some way, but DH and I like knowing that everything is paid for except for tips & adult beverages are of course not included.
When our DD's were little, we enjoyed regular
DDP ( 1QS, 1TS, 1 Snack per person per day), We would do breakfast in the room most days, which worked out great for us. QS for lunch and TS for dinner, we mostly stuck to this to keep within their normal sch. I started playing around with it more and more, I found that Character breakfast worked out really great, and the kiddos weren't beyond tired or asleep and enjoyed this interaction more. But as they got older they need a real meal instead of a quick breakfast like when they were younger. Once they hit about 4 or 5 grade we had moved to DDXDP, Character meal, and a signature thrown in for mom and dad. We enjoyed trying new things, and appetizer and dessert while not always how we order at home but is/was really fun while on vacation. We still go the dinning plan route when we are all together as DD's are all grown up and have families of their own.
I would at least try it once, and see for yourself if it will work for your family.