Had a brief look through a pair at MGF, pretty impressive as was the list price £2.4k.
They were claiming to have far higher light transmittion than Zeiss/Leica, something in order of 95% where as Leica was 74%.
Chappy had huge big data sheet but I was unable to have good look/copy.
You would need to try a pair in low light and directly compare with Zeiss/Leica. Apparently range is from 20m up.
Also heard that the guy up at the range at Kemble has got a pair and highly rates them, search threads on site for his comments.
D