The requirement to pay for the ticket with the card is the major issue for me, at least in the near term. I have several trips on AA next year where I know I'll be checking bags. But, I'm already ticketed. It would have made upgrading from gold to plat an easy choice.
I wonder whether I could talk my way into the benefit even for previously purchased tickets if I offered to upgrade to plat immediately. Not sure why they'd say yes, but who knows? Anyone have any kind of experience with this sort of request for Amex?