I'm paying with my phone via Commbank Tap & Pay [1] and the one part of going overseas I'm not looking forward to is going backwards in banking systems & technology.
Initially, chipped cards were (are?) slower because the approval was transmitted via dial-up (!) or GPRS. The newer terminals (that also support NFC) are using 3G and are fine speed wise. Some retailers even do batched approvals - the terminal does some kind of check and displays "offline approve".
1: https://www.commbank.com.au/personal/online-banking/commbank...