This lens should apparently be one of the best lenses produced by Voigtländer. From my experience with my example, I can't really confirm that. I may have bought a lemon, it happens.
Extremely difficult to focus at f1.7 or near to that even with the focus peaking function on the Sony cameras. I can't even say that it's very sharp wide open, you would have to stop down quite a bit to get it sharp from corner to corner. With my example I'm talking f11 or thereabouts. Not exactly ideal in low light situations. Again, this lens performs best on APS-C sensors for obvious reasons. It's actually very decent on M43 cameras but that sensor is even smaller.
It's not a lens that I will be using often and I might find myself passing it on to someone and I have a few more 35mm lenses that perform a lot better on these full frame cameras like the native Sonnar T* FE 35 f2.8 ZA which is one heck of a lens.