I got my copy of a Jupiter-8 & pitted it against my Industar-61 LD on a G1. Let folks judge for themselves.
1. Industar-61LD @ f4
2. Jupiter-8 @ f4
I took a crop of the upper right corner of each - Industar on left:
They were shot at minimum focus distance, the Jupiter actually focuses a bit closer than the Industar.