Well, I happened upon a new 1.2/50 Noctilux. I confess that I have become enamored with its wide open/near wide open look. However, it is not easy to use well. Wide open it is only sharp in the very center, that means, for instance a portrait with the eye off center, wide open, is problematic. Current philosophy from Leica lens designer Peter Karbe, is to shoot wide open, only stopping down for depth of field considerations. I contend that is a pretty modern concept only possible because of the spectacular high ISO performance of modern sensors compared to traditional film. I think that common film era philosophy was to shoot stopped down and only open up for shutter speed (camera shake) considerations. Leica never developed it's early Noctilux lenses for their unique look wide open, they developed them so you could get a shot in very dim light, their "look" was simply what Leica decided they could live with in exchange for no blur from camera shake.
The current Noctilux .95 is renowned for its sharp, but razor thin image when wide open, but the cost, weight and size are significant, the f1 Noctilux isn't as sharp as the Noctilux .95, but still quite large. The Noctilux 1.2 also lives with perceived softness wide open but that is due mostly to low contrast, resolution being quite good but the low contrast making perceived sharpness low. However the Noctilux 1.2 is much smaller than both the f1 and .95 Noctiluxes, close in size to Summilux 50 Black chrome edition making it an easy carry. And the f1.2 gets contrasty, modern and sharp as you stop down. The new Noctilux 50 1.2 costs a lot less than the .95 and more than a used f1. Buying the 1.2 Noctilux has not been about making a sensible decision on an all purpose lens, it has been about a lens that is distinctive wide open and needn't be swapped out when you want to stop down for an abundance of sharpness. Yes, there is a Leica premium but still, I'm keeping mine, even if doesn't stay on the camera all the time.