I'm curious how the this community feels about the extended school year concept?

I know that in our family, DS learns more and enjoys learning more over the summer vacation since he has time to go beyond the mandated class assignments. So my thoughts are that it would depend on the school environment and the child, but in the reading I've done so far on the idea, it seems that the idea is to reduce the time spent on review so this could be good. Although, if we are going to make major changes to the factory school model, I think there are better options than extending the existing school environment.