When we went for our first time camping on Lake Hartwell we chose Twin Lakes. Enjoyed it a lot. We was on site 9. It was quit private but was a short walk down to the lake, but we prefer privacy over being feet from shoreline. With that said that was last year and the lake was very low. There were many sites that if lake were full you would be from just several feet from water to a few yards.
Will definitely go back, it has been a little hard to get the site that we like the most.
We have stayed at Conross also. It is nice also not quite as nice as Twin Lakes but IMPO Twin Lakes a 9 and Conross a 8 out of 10 for us.
I took a lot of pictures of sites at Twin lake and Conross. I could upload them to a site if anyone might be interested in looking for reference.
We use to do Private campground all the time until I asked about COE campgrounds hear on this forum and I don't think we would ever go back to a private camp ground. Yes COE usually don't have sewer hook up but to me the COE CG experience far out weighs Full hook up private CG.
I've done so much with so little for so long, I'm now qualified to do anything with nothing.