I had the AIS version of this lens which has the same or very similar optical design as the K version. I found it to be a well mannered lens. Sharpness and contrast were good. Barrel distortion is mild and simple without any waviness. It's not generally noticeable except for straight lines near the edge of the frame. I found the bokeh was a little harsh in the background, not rounded as noted above so maybe the optics were tweaked at some point.
I don't recall that my lens flared badly or any worse than any of my other AIS lenses, but maybe I never tried shooting into the sun? I have noticed that early multi-coated 35mm f/2 lenses (C and K versions) are prone to separation between the cemented elements. I have a C version which has separation around the edge of the cemented elements behind the front lens, visible as multicolored Newton Rings. I also have a K lens which appears to have complete separation at the same location, obvious as a large round pearly colored reflection where it should be transparent. I also used to have another sample (with consecutive serial number) with the same problem. If your lens suffers from the same condition it would contribute to flare.