Just wanted to tell you about my experience with using different debit cards for payments in foreign currency. Maybe other can share their experience as well. Over the last year I’ve used following three cards intensively to make payments in foreign currency: Transferwise, Neon, Revolut. My experience with the exchange rates:
If the payment is in a widely used currency (e.g. USD, EUR) the best rates I get with Revolut and Transferwise (a little exception: do not use Revolut on weekends or exchange the money with Revolut before). If the payment is in a less known currency (e.g. TRY, IDR) then use Transferwise. Neon is unfortunately only an option for me as a backup. They use the official Mastercard exchange-rate (https://www.mastercard.us/en-us/personal/get-support/convert-currency). And if you compare this rate with the different exchange rates that existed during a certain day (e.g. here Xe: USD / CHF Currency Chart. US Dollar to Swiss Franc Rates), you will realize that they apply nearly always the (for you) most unfavourable exchange-rate that existed during the 24 hours period. Therefore you are nearly always better off (even if, in the case of Transferwise, a small fee is applied) if you use the live exchange rate of Transferwise and Revolut.
This is just my experience. Maybe others can share theirs too.