I just went through ATL Northside Security Friday. NoS was the only option, but I always opt-out. The very young clerk was quick to come and, not that I'm complaining, did a quick patdown. No junk touched etc.

However, the swab test came back with an alarm. He panicked and didn't know what to do. He didn't even ask me to stop putting on my shoes, belt etc. He left me unsupervised while he went to get another clerk to ask what to do. He then swabbed my hands and tested that in a different machine. He gave me a thumbs up and I was on my way.

I'd have to say Hartsfield may be more laxed than other airports based on my experience.