The Zeiss Milvus 50mm f/1.4 is an absolutely superb lens. For those of you who follow this stuff, it was one of the two lenses that received a new optical design when Zeiss migrated from their now CLASSIC series to their current MILVUS series. For many, it is a lens that they aspire to one day own due to its solid build, sleek design, razor sharp rendition even wide open, and bokeh that completely obliterated backgrounds. I will grant that I've yet to experience any of Zeiss's OTUS series lenses, but the Milvus 50mm f/1.4 was flat out THE BEST NORMAL FOCAL LENGTH LENS THAT I HAVE EVER USED. With very little distortion and vignetting, its rendition of scenes was absolutely clinical in every way imaginable.
I remember the day I ordered the lens. I can't say that I was the proud first owner of it, but whoever owned it and sold it to KEH took good care of it and it looked absolutely mint the day it arrived. I remember attaching it to my Nikon D810 and having my jaw drop at the files it produced. Sure, manually focusing with a DSLR was a complete bitch, but when I was able to slow things down, it made for some fantastic imagery. I even attached it my Nikon FM2n and gleefully pushed frame after frame of film using a lens that was sharper than anything available back in the days when 35mm film was commonplace.
But alas, as time went by and the novelty wore off, I found myself leaving the lens at home more often than not. First of all, it was pretty heavy and added a bunch of weight to my bag. Secondly, while the size of it felt right on my D810 and my later Nikon D850, it felt awkward on my FM2n. This might have been mitigated somewhat if I purchased an F2AS or F3HP, which are larger bodies, but the FM2n is what I had and it just felt strange attaching this lens to this camera. I suppose the biggest reason I stopped taking it out, however, is that the lens was just "too perfect" in a way.
This might sound incredibly stupid, but bear with me. Sharp, accurate, and clinical are certainly very good qualities for any lens and the Milvus 50mm f/1.4 checks all the boxes. The problem for me is that it's pretty rare that I'm looking for really clinical rendering out of a 50mm lens. Certainly for my wider lenses that I might use real estate, I want as sharp, accurate, and clinical as possible, but for standard focal lengths and telephoto lenses, I've come to focus more on interesting (maybe "painterly) aesthetics. In this regard, the Milvus 50mm f/1.4 becomes a pretty boring lens to use. Don't get me wrong, I'm not obsessed with swirly bokeh, soap bubble bokeh, or similar gimmicks (I have already gone through that phase and have since traded in my Helios 44M and Helios 40-2). Honestly, I'm not sure how to describe what it is that I'm looking for in a lens, but I definitely know it when I see it and the Milvus 50mm f/1.4 simply wasn't cutting it for me, which discouraged me from carrying it around even more than the weight of the lens. In a sick twist, I ended up actually purchasing a NIKKOR 50mm f/1.4 AIS which I started using far more than the modern Zeiss lens.
I'll never say that the old NIKKOR lens is better than the Zeiss—at least not in any quantifiable aspect. The decision to finally part with the Zeiss lens was a difficult one for me because it defied all logic that I should let go of one of the finest lenses that I've ever had the pleasure of using, much less owning. In the end, however, I decided that a lens sitting in my cabinet would be better served going to someone that is actually going to use it and the money I get for it better served by purchasing something that I will be more encouraged to carry around at this stage in my photographic development.
After some long nights of reflection, I finally made the trip to Adorama today, traded in the Zeiss Milvus 50mm f/1.4 and picked up a Voigtlander 58mm f/1.4 Nokton SL II S. It's a lens that I've been looking at for a while now and I've seen many photos taken with it. While it may not be as technically competent as the Milvus, it is smaller, lighter, and most importantly, I find the way that it renders scenes to be more to my personal aesthetic tastes. Coming back home and attaching the lens to my D850, I can say that I'm definitely pleased with how things have turned out and I'm looking forward to using this lens for a long time.
If there's a take-away that I've learned from all of this, it is that expensive gear is not always the best nor is it necessarily going to provide the qualities that you're looking for. I dreamed about owning Zeiss lenses for so long and even now, I still have several Zeiss lenses on my Amazon Wishlist, but more important that the cost of a lens, its stature, or ratings, is whether you are personally happy with it.