Now that much more details are available on the HG one website concerning the design and build quality, it certainly looks to me like the $850 price tag is warranted.
With the all the problems I've had with my Vario in just 2 years (I am currently on my fourth grinder) and considering how better the Robur burr set is, this grinder seems like a much better deal in the long run.
The Mazzer Robur or K10 would be nice, but considering the grind retention, size and price, the HG one seems like a much better deal.