In buying a coffee with BTC my main concern will be to have to pay at least 5 cents for a transaction fee.
By paying with card the merchant pays the fee while paying with BTC we pay the fees. I think that's the main adoption problem in buying a coffee with my bitcoin
oh, c'mon! Do you really think 5 cents makes a big difference? I don't think so.
If we all want Bitcoin to be accepted more widely we should be ready to sacrifice a bit at least IMO and 5 cents is not a big sacrifice.