Part of the story is that I wanted a fast lens that I could trade gear for- and nobody had a 'lux of any flavor locally (Cleveland, I could almost be on the moon as far as Leica gear goes!) so I found a Lux, an involved trade we made, and I walked away with a Lux, a 135 Elmarit, and strangely enough, a Contax IIIa. I lost 4 or 5 cameras, 9 or 10 lenses, and ended up with something that works well enough.
I agree that the purpose of an f/1 lens is probably more often best used at f/1, and it's fun to do so! Would have I taken a Lux? Yeah, I would have. Then again, this got me the most for all of that pesky gear hanging around collecting dust...
I'd LOVE a Summilux ASPH!
Note too that much of my picture taking is with Tri-X pushed in Diafine to 1200- a bit grainy, but more importantly, if I'm hand-holding at 1/15 wide open, goin' to 1/8 is hardly an option with a stop darker lens- I'm certain to get worse shots.
And about the 35mm Lux... It was "new," but a store demo. Old style (mid 90's) box, it's been in use as a demo for a long time. It does indeed take "nice" pictures, but the Noctilux does seem to have a better bite. Sadly, that's all I can compare it to- I'll have to throw the J-12 on the Contax, and if IT'S sharper scanned, the Lux goes back to the factory!