I often see row 6 open in the weeks leading up to a flight, with the rows behind it filled. My (probably very faulty) assumption is that those are people who paid for the upgrade, looked at SeatGuru or the like, and saw that row 6 is marked as "Be Aware". I personally think that row 6 is far superior, even with the tray table in the armrest. Sometimes, I try to look even further into my crystal ball and make assumptions about upgrade probability based on row 6 being open, thinking that no 75K would select another row over it at booking. Are there any 75Ks, or anyone for that matter, who avoids row 6 when booking?