If it is Bjørn R. who is doing the owning, then that fact alone gives
me a
lot to go on.

But I grant that YMMV for others. Srsly though, the man does know how to recognize a good lens.
I have both the Noct-Nikkor and the 50/1.2 AIS. Make of this what you will, but the Noct has character and the 1.2 does not. The Noct's backgrounds are nicer. Its renditions are smooth and subtle, not jittery or busy. Noct is for Night: night time shooting between 1.2 and 4.0. I think the Noct, while sharp, has somewhat less
microcontrast than today's "documentary lenses" like, say, the modern Zeisses. The Noct provides a more of a - what word am I looking for ? - artistic?? look to its images. The Noct, however, does not lack contrast.
The Noct paints like a Japanese watercolour while the new Zeisses draw like German etchings. The 50/1.2 doodles sketches in the margins of the morning newspaper.
I don't test lenses, I just use them. So I don't really have much of a vocabulary for describing lens properties.
The new Noct is somewhere in between the old Noct and the old 50/1.2.
Anyway, my original post was intended to be more about the pricing than the merits or lack of merits of the Noct. There seems to be some resistance to the over $3k pricing for a Noct. This is a good thing because the Noct is specialized and not truly rare (yet). So its price should be increasing
gradually.