Only one I'm familiar with on that list is buckhead imports - and I wouldn't go down into buckhead traffic for the life of me. I've not even heard of the other ones before, and don't recall the locals mentioning them. Been a long time since I've had to go to a shop, I'm lucky to have a friend who's a bmw mechanic for my work (whew). So I can't recommend a local place offhand. International Imports stands out (In Roswell/Marietta area, so maybe right up your alley) in my mind.
If you wanna ask hundreds of locals in the ATL their opinion on shops - try the GA forum on bimmerforums.com. (No hit on bmwboard!) But everyone 'factionalizes' across 1 forum or another where they hang out and read - bimmerforums is where the majority of GA/ATL folks pile up at least. (If you want to ask locals questions, local meets, blah blah..)
GL!