The user interface for $CFX is at least acceptable, and the fee structure is quite accurate, although you can also set your own fees, which I really like. As for using this card, I encountered issues in the past (I'm talking about nearly two years ago) in stores and other places. The coins are stored locally, although you can share your key phrase across different platforms. I just received the replacement card, and I really hope the integration with the app goes smoothly.