The subject: an Athenian tetradrachm from approximately 400BC. It's about 25x21mm in size and about 7mm in depth. Due to the shiny surface, irregularities, and depth of the subject, I thought it would be good for testing my setup in its entirety (e.g. lighting, reflections, vibrations, etc).
The lenses:
Schneider Kreuznach APO Componon HM 6.7/60
Schneider Kreuznach Componon-S 2.8/50
FISBA Optik 9/76 7° (random eBay purchase, the angle marking should've been a sign to stay away)
Scanner Nikkor ED 7 element lens
Osawa Tominon 3.5/40
Sigma 2.8/105 macro lens
All stacks were approximately 90-100 photos at 0.07mm increments. Due to different extension requirements, the lighting differed a fair amount between each stack.
APO Componon 6.7/60 (full size)

Componon-S 2.8/50 reversed (full size)

FISBA 9/76 (full size)

Scanner Nikkor ED (full size)

Osawa Tominon 3.5/40 @ f3.5 (full size)

Osawa Tominon 3.5/40 @ f5.6 (full size)

Sigma 2.8/105 (full size)

I'm not very good at objective rankings of lenses but my preference follows in the order:
1. Scanner Nikkor ED
2. Apo Componon 6.7/60 (a close second and the only one shot 0.6x)
3. Osawa Tominon 3.5/40 @5.6
4. Sigma 2.8/105 (a close third and benefited from better lighting due to longer working distance but maybe some CAs near the edges?)
5. Osawa Tominon 3.5/40 @3.5
6. FISBA 9/7.6
7. Componon-S 2.8/50 (worse overall than the FISBA but better in the centre).
The Osawa was the only one I tried at a different aperture (only this one, the Componon-S, and Sigma had variable aperture though) after I was disappointed with its performance wide-open. It ended up being quite sharp and with high contrast stopped down to 5.6 and competed well for the price.
The Componon-S was a disappointment but until I try it stopped down and/or in normal orientation I'm reserving judgement. The FISBA was just a bit of fun as it has a "7°" marking on the lens and was intended as a "spherical test optic for the µPhase compact interferometers" that generates a beam with an open angle of 7 degrees. Naturally it falls off in the corners and is generally poor in resolution.