Nipping to the corner @ 1:1 display, here's the lens at f/2 and at f/5.6:
(Right click the above to see full resolution in a separate window.)
The Summicron-R 35 is a little soft at the extreme corners wide open, gets to excellent 1 to 2 stops down, and produces peak corner sharpness at f/8. Center and well out to the corners is excellent throughout. There's no smearing on the SL (this is one of my lenses that smeared at the corners on the A7). The behavior I see in this quickie test on the SL matches its behavior on film exactly ...
Smearing in the corners with this lens, the Elmarit-R 24mm, and smearing plus significant vignetting/artifacts with the Elmarit-R 19mm v1 are what led to my disappointment with the Sony A7. These lenses perform better on the M-P typ 240; with the SL, they image as well as they do with the R8.