There are so many agriturismos, the choices are overwhelming.

I have pretty much decided that I want to choose one in Tuscany, because that is the area I want to visit in Italy. A place with a "family dinner" option - not just a restaurant - is one of my top priorities, and it rules out a lot of places. So far the frontrunners are Agriturismo Savernano in Reggello http://www.agriturismosavernano.com/ and Podere Spedalone in Pienza http://www.poderespedalone.it/en/index_en.html.

Any input on these, or suggestions of comparable/better alternatives?

The location in Tuscany would be my top criteria.
Look at Terre di Nano and Fonte Bertusi. as well.

IMHO, Podere Spedalone is in a much better location. It is very central for visiting many towns and experiencing the most lovely part of Tuscany countryside. The property looks nicer also.

Consider La Fonte, which is in a lovely location (can't be beat) just outside of Pienza and I've heard serves excellent family style meals (lunch and dinner)-
http://www.lafonte.toscana.it/en/

By the way, Fonte Bertusi (suggested by Bob above) is my favorite place to stay (~8 times so far, 1-2 weeks each time), but doesn't serve dinner (their breakfasts are very good though). It is located a short walk or a 60 second drive from La Fonte, where you could go for dinner. You do not need to stay at La Fonte in order to have dinner there. They both also a 5-10 minute drive to Pienza or San Quirico d'Orcia, where there are lots of places for dinner.

http://www.fontebertusi.it/en/