With kids, one thing to consider is the pool. The Moderate resorts have a slide but I don't think the value resorts do. Just a thought. I know with my kids, the pool is something we have to look at when considering where we stay.
Also, the values only have a food court and the moderates have a food court and a sit down restaurant.
I prefer the moderates, The rooms are a little larger than the value. Also, you can get a small refrigerator for free, they are $10+ a night at value resorts.