I do not own this specific card, but I do own 2 german credit card (AMEX Gold + Hilton Visa). There is no catch really and no hidden fee as long as you pay the entirety of your bill every month, and do not use this for cash at an ATM. I have never paid yet a fee on my credit card.
BTW, AMEX acceptance is OK here, maybe even better than in France. Although the place where I live is special due to the large amount of american.