I've been working on a lockdown project, refurbishing an early version of Sigma's slow masterpiece, the 180/5.6 after I was fortunate to locate an optically decent copy in Germany.
With only the sticky zen coating to worry about, the project wasn't as big as it might have been, but that zen gets everywhere. When its softened by the solvent, (try WD40 first, label remover last), it can creep into the focus ring, so you have to be very sparing. Saving any of the stencilling is a bonus if you are going to get rid of the stickiness.
This lens delivers more working distance on full frame than my Irix 150mm. If fieldwork is your thing, half the size and weight of the Irix is a big plus. DOF is thin, so I find myself stopping down to f/10 or f/13 most of the time. Would I like 1:1? Yes, but this lens is a scary sharp apochromat and cropping is the default option.
These are all handheld, available light, JPEG OOC with only Windows Photos magic wand applied in post.