I have often compared foreign charges on my CitiAA card with those on my MBNA card. Visa seems to charge the same for both of them (about 1% over interbank) but Citi (and most other Visa cards) then adds on an extra 2%. MBNA doesn't. Of course, you get miles with CitiAA and not MBNA but they're not worth the 2%. Never could find a card that gives AA miles and doesn't charge the extra 2%. Has anybody?
I can't imagine Amex charging less than the interbank rate before adding their 2% or so. Otherwise, how could Amex be the best choice?