abount refund:
apparently it's not at all what we hoped for.
As far  as I understood from the HF thread, all they
pay will be the USD price of the unit.
That is, we only get a fraction of the BTC we paid.

I wouldn't accept that.
(of course now every HF customer would gladly accept a refund
of BTC he paid. But that's not on offer, that's something we would have
to fight for.)