I remember your travels and post so figured your really researched it.Ranking is hard but ill give you some cities I have above ATL
-Louisiana in general but ill say NOLA
-Savana GA
-Charleston
-Houston
-Miami (Soulfood + Latin + Afro caribean)
Mind you, Ive spent more time in ATL than all of these cities combined and I find ATL's food scene to be a gimmicky and repetitive. AND.. the soul food in general seems a bit watered down in comparison to aforementioned cites or places like Mississippi, Memphis ETC. too much copy paste seafood boils, wing spots. The places that are trying to be "trendy" and experimental don't do that well. I really don't find that culinary identity/soul in ATL the way that the south in general has it. Ive never been anywhere where people hype more restaurants that are mediocre to me.
Good shout