We have camped here before and it is a nice park if you like water activities. Having a boat, canoe, kayak, is a must otherwise, you'll get bored quickly! Options are to go to the beach across the street or drive down to the Sebastian Inlet State Park. There's the McClarty Treasure Museum south of the inlet which is cool to see. Also, Disney has a resort in Vero Beach (a few miles down the road on A1A) which has a character breakfast on Saturdays (yes, it is very pricey!) which the kids will love.
It is a very nice clean campground. The ranger station sells firewood for a very reasonable $6 per bundle (cash only). The location makes it a great place to see the sights such as the historical Kinglsey Plantation and Ribault Club. The ferry to Mayport is also fun.