On our '07 trip they were mixed. Tough to get ADRs or really busy parks we TS for late lunch. The rest we did TS for dinner.
Next year I'm planning all TS for dinner. With young children it might be best to try for early dinners on the Monorail and head back. CS is just as good if you don't want to leave the parks. It helped us get a really good spot for Spectromagic.
I have two young kids also, 3 and 6. We started out with mostly TS for dinner, but then I started tweaking things around due to the parades and shows we want to see. This trip, we're seeing Spectro/Wishes, Fantasmic, Illuminations/Candlelight Processional, and going to
MVMCP so for us, I thought trying to squeeze in a TS dinner might leave us feeling rushed to get somewhere on those nights - except for MVMCP where we do have the Plaza before the party so we can be "right there."
Add to that the fact that a relaxing sit down meal might be nice for the little ones (occaionally) after running in the park for a few hours. It sort of "forces" us to take a break. Then we can head back to the park whenever we want to and not have a timeline, except for when the parades start. We have two TS lunches for this very purpose: CP and WCC. We do have 3 breakfasts as well, because some meals I thought would be better at breakfast - Akershus, CRT, and Chef Mickeys are all Breakfast meals for us because of the reviews and/or character interaction. So now I am left with only three dinner TS! 'Ohana, 1900 Park fare, and the Plaza (for MVMCP night). So we have 3 breakfasts, 3 dinners, and two lunches, so I sort of think that's an OK mix.