I mean it just depends. Yes on paper GLD isn't that much better than a credit card especially if you fly for business during peak times. I guess just comes down to do you want to be loyal to AAdvantage? Do you want to try to redeem miles for QR or CX J class (assuming the latter ever becomes an option again)? Do you want the option of lounge access with the Citi Exec card? If you don't care about these things then yeah you might just be better off buying the cheapest ticket.