Just a quick note. American Airlines changed the domestic upgrade policy on March 10 2017. Previously, it was Status followed by date of booking. So book first and get upgraded first. This didn’t really reward the late booking business travelers who spent the most. As of March 10th Elite Qualifying Dollars (EQD) now take a roll in figuring out where you land on the upgrade list.
I do not have all the details yet but I am sure those will leak out on the awesome travel blogs soon enough.