Here's the truth: a smoother film advance will not make your photos better.
I have a Leica IIIf, a Zorki 4, and a (knob-wind) Fed 3. I rarely use the Leica. It doesn't take better pictures than the other two - but it has a worse viewfinder. It is fun to shoot a roll through it sometimes, but I actually haven't picked it up once this year.
For me, the quality of the viewfinder is more important than the smoothness of the film advance. I want to compose photographs more than I want to wind film smoothly. The III series cameras make nice conversation pieces, but they're really just novelties so far as actual picture taking is concerned. And for what it's worth, that Fed 3's knob wind is near as makes no difference, just as smooth as the IIIf's.