I have three Koni Omega's right now. I have mint condition 58mm biogon clone. 90mm tessar. I believe in them after my Mamiya Super 23 Press failed on me at a wedding, the focusing went out of alignment. So, I chose the Koni Omega and never had such a problem again. They are tough. The flash cord never fell out which saved me many wedding pics. Of course, it screwed in!
I took the handle off of a Koni and used it to customize a Stroboframe R7 bracket to perfection.
The sharpness figures for the 90mm Koni Omega are as sharp as Zeiss 80mm when stopped down to f11. That is, all excellents. Someone said the Hexanon lens was sharper than the Omergon or whatever it is spelled like. Anyway, it has a very sharp lens when stopped down.
What a tough camera! Focusing was fast for a rangefinder! And you could calibrate the lens or the focusing handle for flash distances for perfect fill in flash.
I used 220 film, and never had a scratch. It advances film really fast. It looks so wierd though! But once you get past it's ugliness, you realize that everything is placed in a logical position. So much better than trying to use a Mamiya RB 6x7 handheld!
The younger photographers here don't appreciate rangefinder cameras. They have auto everything. There's a place in my heart for the Koni Omega 6x7.
...Timber...