Sadly it seems the company has closed down. Flights cost more than US$400 per person per hour, so it wasn't cheap, but still required $5 million a year sponsorship to continue operations. Apparently there is a shortage of helium which had increased tenfold in cost over the five years it flew. It carried 20,000 pax, so it was a pretty big operation for a while.
I was trying to find out a bit about the engines. Does anyone know about them? Ran out of Google time...