I have a Zeiss Ikon Super Ikonta 531/2 with f3.5 Tessar. I bought it mainly because I think it is beautiful =). The lens is sharp, but as it is not multicoated, the contrast could be better. The film flatness is also a minor issue in this 6x9 camera. And it is not easy to shoot this pretty dinosaur handheld at times longer than 1/200; the shutter release is in a rather uncomfortable place, I guess that is one reason, the 105mm focal length another. So I don't really think it is a nice camera to shoot with. I have used a 6x6 Super Ikonta (I guess Super Ikonta III) once years ago, and I recall it was much easier to handle.
I also have a Fuji 645W, the old model from early 80s, with 45 mm lens, (equivalent to 28mm for 24x36). It isn't bigger than my Super Ikonta really, shorter but thicker. It has a sharp lens, built in exposure meter and more economical film size, 6x4,5. Of course it isn't a folder, but that can't be the real issue here, size is, right?