The Georgia State Parks system has many benefits over specific site reservations.
1. You reserve one site form a group of sites that fit your size RV. Example, you reserve a site for a 30' RV and someone else reserves a site for a 20' RV. This keeps someone with a small RV occupying a big site.
2. You get to choose your site upon arrival. Unless you know your site preference from previous visits, you are left to just look at a map, or in rare cases, a thumbnail picture. I like choosing my site in person.
3. You can change sites without the approval of the office.