I just got back from a trip to Europe (England, Sweden, Finland, Estonia, Germany).

Automated kiosks in England (tube and train tickets at Victoria) and Finland (metro station at the central railway station in Helsinki) worked great. The automated kiosks in Stockholm told me to get lost, I had to load my SL card at a convenience store where I could sign a slip of paper.

Restaurants and other stores in all countries worked without problems, and I think they're used to us Americans and our silly cards as the merchants were rarely surprised when the signature slip was printed for me to sign.

Cards used: Amex, Citi MC, Discover, all with EMV chip + sig.