Maybe somebody has image samples that show the differences?
Here is a picture showing some differences.
The AF and AFD and PQ lenses which are newer are frequently Schneider. The older SLX lenses are Zeiss. There is no 'vintage market' for those older SLX Zeiss lenses so they cost less. However they won't work on the Hy6.
$500 Zeiss 40mm with $2000 Schneider 40mm.
Handheld sharpness? The mass makes angular moment of rotation of the body pretty high with respect to the mirror so that 1/30 or 1/15 is feasible with the prism, 6000 body and Zeiss lens.
The much lighter Hy6 system counters with a 'Mirror Pre-Release' button in easy reach, allowing nearly the same lower handheld speed. Both are leaf shutter cameras.