Just purchased this lens for wide aperture magic.
It has its rather strong character by today´s standards, it has heavy vignette wide open, but it is funny lens, that gets much better and sharper at f/2.8-f/4.
Given the fact that I would use auto-stacking for macro work, I am not sure where will this MF madness (along with the 85mm f/1.4 Samyang) lead me, but these lenses really push me to shoot and have a fun.
With simultaneous purchase of macro tubes, here is an introductionary shot.
"A potato satellite":