A sharp lens, the 55/2.8 Ai-S. You like it?
Yes.
Partly for sentimental reasons, as this lens was hailed (in France at least), by the mid-eighties, as one of the best standard lenses ever, and an alternative to the more conventional 50/1.8.
I've been using it every now and then since about 2012, on the D800 where it does not disappoint, then on the Df but less often, as I bought a Zeiss planar 50/2, then a fresh second hand Milvus version of it (with vastly improved coatings).
The Zeiss 50/2 Milvus seems better in
every respect, and has become one of my most frequently used lenses. However the older Micro Nikkor is a solid performer in every respect too, is lighter, and I got a matching extension tube. I used it a lot with my OM-D for macros.
The only real drawback of the Micro Nikkor is its tendency to flare, so I won't call it an allrounder. Same with the Summicron-R 50/2 for instance, which is insanely good (two lanthanum elements inside may partly explain that...), but for the coatings. Coatings have been improved a lot since the late seventies / early eighties. Otherwise I do not have marked preference for recent prime lenses compared to older optical formulas.