This is the second version of this lens.    It is somewhat large and all metal.    It has an automatic aperture.   The glass specs are the same as the first version.   

     The coating on this lens is not as advanced as the AE models.   Expect chromatic abberations in clipped areas.   Flare testing is represented in the pics below.   Wow.   Almost no flare shooting into the late day sun.  A spot just above the sun and there is fringing which can be seen at 100%.   This is Impressive when you consider that this was not a pro grade lens.  For a comparison, take a look at the Vivitar 28mm f2 in the same lighting here.
     This lens was harder to handle on my M3 than my AE version.  It is heavier, wider and longer because there is a very large element inside the lens.    Focusing is a bit of a guess.   I also noticed myself camera shaking a bit more than I like.
     Sharpness is good at f3.5 and excellent at f8.    Corner sharpness is excellent, mostly due to the massive correction element inside the lens.
     Distortion is noticeable on a sub-frame body.    Keep that in mind if you plan to use it as a walk around lens.  
     Bokeh fringing is very well controlled.  It can be seen faintly at f3.5 but disappears at f4.