Right now the absolute quietest place in the airport that you can go is the new extension on the east end of A concourse (A71-81). It's a decent walk (10 min or so), but every time I go down there there is literally no one down there. It's new and clean, and has outlets and little work stations. You can be down there during the busiest bank of the day and be completely secluded. It's my new favorite retreat, at least until they actually start using those gates for more than just hardstand parking. Eventually they'll be sticking UAX flights down there, and then it'll be a zoo. But for now, that's the spot.