This is quite a fascinating thread... I moved to Germany, have an Amex Plat, and am looking for a card for use when Amex isn't accepted. Either one of the PayBack Visas, or the Lufthansa Miles and More card, all look ideal for this.
Because of already having the Amex, I am leaning towards one of the PayBack Visas purely because of cost, but maybe the LH card does deserve a closer look?