Was on an MCO-ATL flight last July on a brand new A321. It was the 8:30pm flight (last flight of the night) on a Wednesday. I was UGd at the window and the flight went out with 11 empty FC seats out of 20. Row 1 was completely empty. There were only 30 pax on the entire flight. The FA told me that he was on a 753 once and there were only 5 pax on the flight. He let them all fly in F.