We were lucky enough to snag 3 days in May at this state park. It was a great stop if too short to really enjoy the amenities and just relax.  Sites are mostly back-in, main park roads were in good shape, but the campground roads were rutty and tough.  Camp sites were spacious with packed sand and dirt, and usually some foliage between sites.  We were at the Amelia River campground which appears to be the older of the two campgrounds in the park.  Plenty of beach area, sunset views, biking, and hiking.  Do take time to visit Fort Clinch for its historical perspective.  Fernandina Beach is right outside the park gate, but you would never know it from the campground locations.  Very private and quiet.  Bath houses were very convenient and well maintained.