Along_the_Wire It’s shit for the US as they really fucking rip you off on currency conversion and fees
I got my Amex mainly to be able to use in the US, and never found that to be the case tbh. I tend to use cash everywhere and keep cards as emergency backup, but have paid for all my sports jerseys with Amex and the exchange with fees has never amounted to much more than what I got for currency conversion here in the UK.
In regards to Amex here in the UK, I’ve seldom had a issue using it for any goods or services.