I had a Zeiss Super Ikonta III but sold it because I didn't like the IQ or the ergonomics.

I sometimes contemplate getting another folder hoping that I can improve in the IQ and ergonomics but I'm wondering if this is wishful thinking. I know the Tessar is no slouch because the ones fitted on my Rolleiflex is superb so I'd go with the Solinar and Skopar (over the Heliar).

The two classic folders that come to mind are:
-Agfa Super Isolette
-Voigtlander Bessa II

Then ofcourse there are some modern folders/compacts (Makina, GF670, GS645) but I'm interested in exploring the classic ones. The classic folders should be cheaper, smaller, sleeker, but less ergonomic. The modern folders should be more expensive, larger (but small for MF), and more ergonomic. Image quality depends on taste but I think that all of these should be an improvement to the Ikonta because of the inherent flaw (front cell focusing). The Ikonta wasn't too bad at a distance but up close it left me wanting more.

I'm not so concerned about the IQ because that is very dependent on condition but more the reliability and ergonomics.

Reliability:
Is one of these cameras more reliable than the other? The S. Isolette has a film advance issue, does the Bessa have relibility problems?
Ergonomics:
Is the aperture ring and shutter speed clickless and do you cock the shutter on the lens? I really hated that.

I think that I'd opt for something more modern but I just didn't want to dismiss these cameras right away.