Interesting ! Especially where he writes :
"In regards to Leica M Mount lenses using adapters…The A7r has issues with the 12, 15 and 21mm focal length, even 28mm to some extent. The A7 had some slight vignetting with the 15 and 21 but no real color shift. Not nearly as much as the A7r. So if you are one who was planning on using WIDE ANGLE Leica M mount glass, go for the A7."
More or less what I feared it would be : the lower resolution Nex like the Nex-6 were already doing better than the Nex-7 with RF lenses. Apparently those specially arranged photosites only serve to compensate for the disadvantage due to the higher resolution but aren't able to fix the problems of the WA RF lenses.
I'm not sure that I've found a back for my Zeiss Contax G 21mm F2.8, because the first samples I have seen showing WA RF lenses on the A7 had a lot of smeared corners, not only vignetting or magenta shift :-(