I didn't realize that MNBA was one of the "good guys" who didn't add their own charge on top of the card company's 1%. If you're sure that's the case, and you get 1% cash back besides, and they use an acceptable exchange rate, that's the way to go. Afaik the only thing Amex has going for them is MR's, valued as you personally wish but in reality 1.5% or a bit less.