I’m 6'2", so Main Cabin Extra is a survival requirement for me. I usually get it for free as a Platinum member, but on my last flight, I was traveling with a friend who had no status. We found that the best way to secure those extra inches is to just pay the seat selection fee during check-in. Sometimes the price drops right at the 24-hour mark! It includes free booze too, which made our delay out of Chicago much more bearable.