The summer one often is less fun because of the heat. A wine buzz in 97 degree weather with ridiculous humidity isn't all that great. Plus, you have to keep cutting it with water so you don't have heat stroke. That said, if Mrs. RC and I have our schedules open, we try to go.
VA wine is quite good. The general consensus is that VA is about twenty years behind California on wine. However, twenty years ago, CA wine was incredible so I don't mind "slumming it." VA has a good variety of traditional wines and fruit wines, and even some crazy novelty wines you'd never buy, but will drink at a festival. (Hot pepper wine, anyone?)
There's a couple duds, but if you go with me I can steer you away from them. Though really, since it's a flat fee to taste everybody's wine, you might as well try the bad ones too. After all, one man's trash and all that jazz.
There are bands that are forgettable, and the food runs from stock carny to cheap snooty. Go for the wine, which is worth the trip.