if youre using pin, obviously hold a hand over machine while entering.

and pin obviously requires at the table, and they dont know if you dont have pin.

i was annoyed that tax was included in tip percentage. (i knew it would be, but server said it wasnt.) im guessing restaurants sometimes take it (the tip on tax portion) rather than server.

amex is best regarded for disputes. to the point that they may help with fraud, and merchants complain.
at one point diners club was also well regarded, maybe only for business, and i think it went downhill.