I'd love info on the shadows of Atlanta, myself.
Look for this guy Kirk, here on forums, and ask him nicely to send you some info. We had a PbP started with him as GM...in atlanta, and even we never make it ot the team meeting point, his background article for the area has some beautifull ideas.
Being fair, I wasn't really using Atlanta, just north Georgia which brought part of Atlanta with it.
The only part of canon that I had - have - trouble swallowing is the height of the Cord Mutual building. 500 stories? When the next highest (the HTB), next door, is "only" 180 stories? I wasn't going to rewrite canon, I just wasn't planning to mention it even if (ever if) the players got into it. It's my sincere hope that if a new book gets written with Atlanta in it, those two buildings get retconned smaller. For reference, real world tallest building in Atlanta is 55 stories and it's currently the 9th tallest building in the US (Bank of America plaza aka the Stubby Pencil). Recommended retcon? 125 and 80 stories, respectively.
I'm not as disturbed about Stone Mountain as the Wyrm is, but that's because I'm from Colorado and I've seen Cheyenne Mountain. Yes, the top of the mountain is vulnerable. Hollow it out some, however, and it's extremely defensible even against mana strikes from Kennesaw Mountain.
As for the "difference", I just looked at the way the people here already are and built from that. And for that... In most of the US, Faulkner is allegorical literature. 'Round here, it's just typical family tales.