I think the idea is nice. But the implementation is not yet ideal — not surprisingly for a new app.
Am I missing an option or do I really have to re-enter the information that is already available in my address book?
And if a piece of information used in multiple cards is changing (e.g. address or phone number changed), do I really need to change it in all cards one-by-one?
I would prefer to be able to link HiHello to one of my addressbook entries and then select which fields of that entry to include in any given card.