The 35f1,4 was Leicas response to the Nikon 35f1.8 and to some extent the Canon 35f1.5 in the early 60's. I have had one, in one form or another, since that time. So, it is not the sharpest 35 around, but who cares. IF you were shooting at f1.4 in the early sixties, you probably shot either press or magazine work. Color was still a bit of a novelty and editors were leery, because it was expensive to print! They wanted shots that made it possible to write a caption and identify who,what,when,where and possibly why! Razor sharp images were a bonus, but not really what counted.
The first generation of the 35f1.4 wasn't that good, but nobody rejected a shot because it had "look at the come here, and the field curvature is bad or "mechanics" like that" OK, occasionally they grunted about flare "Oh, cant get the face of that guy - I will cut him out".
I still have one, a late one, #34xx xxx (too lazy to look up the number!). I still use it and it is not bad at all. My Nokton's, the 35f1.4 SC's are better - but the Summilux works well too. Just keep spotlights out of the frame.
The thing with vintage lenses is - they do have personality and sometimes that can improve on an image. OK, my big beef with the 35f1.4, even my late one, is the close focussing to 0.9m only - on the other hand, if needed I can crop it.
I like what you guys have up on this thread - some good shots. They would most likely have been just as good with a Nokton, an Asph Summilux or a Canon 35 or any of the multitude of 35 lenses around today.
A lens is just another tool - the quality of the work depends on the skill of the worker using it - more than anything else!