F/8 test of the new 35 Ultron:
That's on a plain A7. No mod. Maybe it's the best RF 35 I've seen on this camera for landscape.
He has an album with a few more shots including colorcast test, which seems to show none at F/8 and some shift at F/1.7.
Here is a thread with samples and vigorous discussion of the lens on Leica and Sony.
NEW Voigtlander 35 1.7 Ultron M mount - FM Forums