I prefer late fall to early spring in the pines because of the cooler weather and the absence of deer ticks, eye diving gnats, chiggers, deer flies, and spider webs in my eyes, hair, and mouth. However, if you never get out in the summer you'll miss seeing things like fence lizards, various species of frogs, orchids, pitcher plants in bloom, blueberries, etc. I do generally restrict myself to hiking on dirt roads during summer though because experience has taught me that coming into contact with grass and foliage even briefly can leave you with dozens of chiggers on your legs.
I'll hit the Batona Trail again as soon as we get the first hard frost...which hopefully will be soon.