Thank you very much for the link to the photographs Benny!
They showed me a lot of information about both lenses, I did not know, especially, how they handle pointed lights within the image at certain apertures.
As I see it, neither lens would fit into my concept of lusting after a 50 Summilux ASPH with a stop more light (the new 0.95 Noct might be but is absolutely out of the question).
The Summilux has quite all optical details, I want corrected, the Noct and 1.1 Nokt exhibit with the penalty of being slower but in a smaller package.
The Nokton though looks like a very competent tool for some graphic and architectural work with interesting background, as long as it is close up (as it exhibits the batwing coma with further lightsources). I like for this topic your photographs of light patterns in the portrait background very much.
Thanks again for your comparison - very helpful.