My 2c: best use of qff is business class to europe on points in classic seat bookings (256k points). After you pay the card's annual fee and airline taxes for the flight, you get between 1.5 to 2.5 cents per point value. On that basis it is not worth paying 3%. If you can buy things on Paypal and list your Amex card as the primary default, often you can get the points from the Amex card where normally a merchant won't accept it.
It used to be easy, but now you have to work hard if you want "free" points.
It used to be easy, but now you have to work hard if you want "free" points.