Took out my m42 Sears 80-200mm f4 Macro for a spin for the first time in a very long while.
The lens isn't particularly sharp at any aperture (but not particularly bad either) as you can see from these pictures (all taken at f8-f9). I will say however that this lens is very easy and fun to use, for the 10 bucks I got for it originally it really wasn't such a bad deal. To me it's usable unlike my Pentax-M 200mm which in my opinion is very difficult to nail focus with. Another thing to mention about this lens is that CA is pretty bad but it's really easy to correct for it.
This thing really does pack an old "filmic" look into every shot, I could see myself taking thing lens out with a purpose. Perhaps as a softer portrait lens.
Anyways enjoy.