Postwar Contax RF 50 1.5 (Zeiss-Opton Sonnar 1:1.5 f=50mm) vs Jupiter 3 from 62 (ZOMZ)

As the title suggest, I am deciding between these two faster 50 from that era. As my understanding goes, the Russians recomputed the glass for their needs and ability to produce. Also, there had to be some development in terms of coatings as well. (Be it progressive or regressive) My question is... did somebody compare these two lenses side by side? How are they? If so, which one would you buy if the price is the same?

I am planning to use them on kiev 4 as well as a contax IIa/IIIa.