This was my first experience camping at a NC State Park, and it exceeded all my expectations! I had been warned to get there early on Friday, because the sites are first-come-first-served, and that couldn't be more true. We arrived around 2:30 and literally took the very last of the shaded, "woodsy", sites. There are lots of newer sites that are in a large field, with no trees - but personally, we were looking for the more private, shaded sites. I would say by about 3:30/4, the "No Vacancy" sign was up. I was surprised - but it's definitely true - Go Early!!
The bathhouse was clean, well stocked with paper, and had warm water every time I went. The grill/firepit was adequate, and the picnic table was standard. The park itself is beautiful, and large enough to easily hike for 2/3 days without getting bored! There are lots of areas for trout fishing as well, and a short drive takes you to the Blue Ridge Parkway.
Overall, I highly reccommend Stone Mtn for a great camping experience. I was very impressed, and will definitely do it again!