I've been attending summer concerts here for a few years. They are generally pretty good with a low cover charge. They have a small dance stage too. There is plenty of seating if you arrive 20-30 minutes early. Otherwise bring your own lawn chair or blanket. Definitely bring bug spray.
They have a good selection of whites, reds, blush, and dessert wines as well as beer and snack foods. If you buy wine glasses, you can bring them back on future visits to save a few bucks.
The only negative for me, and it's really not their fault, but a lot of people bring their kids like it's free child-care. If you can get past that, you'll have a good experience.