Originally Posted by
Wpgjetse
I don't know about Chase, but Amazon Visa does not use the current trading rate. They use the exchange rate(no fee) set by Visa International, which is still higher than Amex. Rogers Plat MC also uses MC International exchange rate, which is higher than Amex.
My understanding was the Amex rate was often higher. And that for any currency other than USD, Amex would convert first to USD and then CAD, doubling the fee.
A quick Google of "Amex vs Visa vs Mastercard foreign exchange" shows articles with all sorts of conclusions but the top one, admittedly with US cards, suggests they are all more or less the same and Amex is almost never the best.
If you have better info I would love more details. Or maybe I should try it out for myself...