Back in the sixties I spent a while trying to decide between a Fed and a Zorki, and ended up getting a Zorki 4. Maybe it was because it came with a faster lens. I was quite happy with it. The lens was soft at wider apertures, but not unusably so, and it performed well when stopped down. A good lens hood was essential. As Mitica says, the quality of the lenses varied widely from example to example.
Best,
Helen