I lived there for a couple of years for grad school, and flew out about once a week in my final semester for interviews. The airport is a super well-oiled machine, it doesn;t really feel different from say, San Francisco. IMO it feels way more comfortable than LaGuardia, which is easily one of the worst airports I've been at in the US.
I hope it feels different from San Francisco, which is a total unmitigated disaster for anyone coming in from an international flight on weekends, and not particularly efficient even for domestic flights.
Atlanta resident here, couldn't agree more. It has always been the most efficient airport for me to fly out from, so far...