zenzanon S vs zenzanon PS

I have a Bronica SQ-A body and a 80mm and a 150mm; both zenzanon S.

I shoot some slides but mostly print film. My enlargements have been

to 20x24. Does anyone know if the PS lense would give different

results compared to the S and in what way would it differ and to what

degree?

The PS lenses are reputed to be sharper and more flare -resistant, though I have hung onto my 50S (because the filter thread is the same as the rest of my lenses wheras the PS version isn't) and I can't see a huge difference between that and my 80PS and 150PS, both of which give me good results. One benefit that I find important is that the PS lenses have 1/2 stop clickstops where the S versions don't.

Personally I don't find the results from conventional printing processes satisfactory at 24" sq. and indeed I wouldn't expect any MF lens to deliver this consistently. So if your implicit question is "would trading up to PS lenses help me to get excellent 24" prints?" My answer would be "better, but not good enough" At that size you'd see a bigger difference from drum scanning/Lightjet prints from trannies than anything the more modern lens will produce.