F40mm F0.85 for EOS-M. No you heard it right!

I never know F 0.85 even exist and here is one for my beloved EOS-M.
Considering the size, small format and then excellent sensor of EOSM and then beyond imagination light gathering capabilities of this lens, this should be a fantastic combination for Wide (Almost) Astrophotography but then at the price offered, I definitely need more info.
Does anyone knows about this lens or owns it??
Like to hear any input or thoughts.

LINK

As you see in the link, lens is also available for other mirroless like Fuji and Sony.

For $2100 plus the cost on an EOS M, I would rather buy a 6D and 50/1.4. Probably could squeeze in a Samyang 14/2.8 in the FF package too for that cost too.

And I have tried my Sigma 30/1.4 for astro and it is much too long for wide field and too short for anything deep sky. 40mm on crop would not excite me for Astro.

You can get stupid fast 0.75 x ray lenses for less than $300, but they will be macro only.

http://www.japancamera​hunter.com/2014/03/thi​nk-lens-fast/

But yeah I'd rather go with a Cosina made 0.95 voigtlanders, way cheaper and fairly certain the quality will be better.

if metabones ever releases their EF-M booster it can be just as fast as a 0.85.

you can get an A7 + speedmaster 50 for that amount of money..... gets you to ONLY F0.95, but it's FF

IMAGE LINK: https://flic.kr/p/obhJ​p8

Over all i prefer the Zeiss 50mm f/0.7

All those who like fast lenses on DSLR cameras should read this:
http://www.dxomark.com​/Reviews/F-stop-blues

Microlenses on the CCD/CMOS - and the sensor itself limits the angle the light is relly used!
So a f/1.0 lens does not collect double exposure than a f/1.4 lens!

In Canon DSLR this is equalized with higher ISO - without user knowledge. As soon as the lens is a bit unmounted - no longer electrical communication between lens and camera, the camera acts real, without this compensation.