Just came back from a trip to Italy and Greece. Have not encountered any DCC in Italy. In Greece every ATM threw a DCC prompt in my face but it was possible to deselect it. The rate was actually pretty good (1.120 vs, Visa's 1.118). Credit cards at a couple of restaurants and shops also offered DCC post-PIN entry, with USD being the default choice. In every case I was asked whether I wanted $ or € and in every case my choice of € was granted without further discussion. At one restaurant the waiter actually suggested that I choose € before I had a chance to respond.