I just got my first Barnack-style camera, a Leotax TV. I bought it for the lens attached. I bought a IVSB2 on the same day with the intention of unscrewing the lens off the Leo and sticking it straight on the Canon. Both bodies are CLA'd and finders as good as it gets.
The postman gave me the Leotax one day early, I played around with it a bit. 'This is cool, but I can't wait for the combined finder one' .. next day the Canon gets here, and it's too squinty.. pass. Turns out the dual finder system works just fine for me.
So I'm keeping that Leotax TV.. which makes me wonder, how does it stack up to a IIIg?