I have an Amex card because my work forces me to take one. But I don't find this a "luxury" experience at all. It's really hard to use the damn thing, for example try to get a taxi at the rank in Paris Charles de Gaulle. 90% of the drivers refuse it and the ones that do accept it often pretend the "machine is broken" later.

In other countries like Romania the taxi drivers just laugh in your face when you try to pay with an amex. I hate that thing but our stupid HR VP from the US forced it on all of us. Probably gets some nice kickbacks in return.