The last time I transferred money to someone it cost zero, and it took a few seconds. The same for recurring transfers to me. Last time I transferred abroad I think it cost £20 on a sum of several thousand for a swift transfer, which isn't terrible, and most importantly, the transfer was verified against identities and there is a record on both ends. Same with credit cards abroad and at home, except with much lower fees and strong guarantees against fraud after the payment.
Is it being used presently by lots of people on low incomes to transfer money? What if they do and it drops 10% on the day? How would they acquire it easily? How would they exchange it easily and quickly for their local currency?
I'd love to see a digital currency which actually competes in a meaningful way with the convenience of digital cash, but Bitcoin is nowhere close. It has serious issues with volatility, speculation, acquisition, storage and lack of regulation/insurance, all of which mean I wouldn't touch it in its current form.