No, we don't charge an exchange fee if all you do is load up your card. It would be
1BTC x $600 x 0.975 = $585.
That's good, so I only loose 2.5% in total.
One more question. When we recharge the debit card, can we specify which currency the btc is converted to? For example, I buy and selling in GBP on the exchange, but I want to use the card in Europe. Can I choose EUR upon recharge, or all funds are always converted to USD?