I'm with K20
AmeX is definitely not as popular as it used to be. My mother came to that realization on a trip after I warned her to get a US debit card bank account, but she was afraid of change. Use your perks card since you get a good return and earn miles on any trip back to Germany.
"I don't fly much at all, most of these are from bonuses for signing up and Dining for miles (i get the 5 Delta points per $ spent)"...and people wonder why Delta reward tickets are so hard to get.