aleksanderpolo,
The CV28/2 is an oddball. There is something in the way it draws that is very pleasing to my eyes; the OOF areas and the transitions (or how it should be described) are great. I wasn't very impressed with absolute resolution, or "sharpness wide open". There may be sample variations though as some describe it as very sharp. Anyway, that isn't the most important feature of a lens in my opinion.
The build quality is excellent, the handling good and the size is fine for our small cameras. The corner/border smearing is pronounced at f/2 and f/2.8, clears somewhat at f/4 and is fine for most work at f/5.6. That may or may not be of importance for you. To me it was a bummer. I hoped the lens should work as a sort of trusty work horse, suitable for snaps and demanding works, just as a traditional 50mm normal lens also if somewhat on the long side.
There is a focus shift problem with the lens. That doesn't matter a lot provided you adjust the focus after having set the aperture. For use with a rangefinder camera that is a bigger problem.
After having seen several excellent images from this lens I bought it new. That was good as the store accepted a return.
I haven't used the CV28/1.9, there I just trust reports saying it is good.
There are obvious construction differences between these lenses and I think the smear problem is due to the exit pupil distances.
Here are two samples from a test series with the CV28/2:
and
Try to get hold of a copy you can try for yourself. It may well be worth it depending on your needs.
regards,
/Jonas