<p>John Kendall, "Fujica 690/100/3.5 + Auto Up and Norita 66/80/2 lens are practically the only medium format cameras with which you can comfortably take head shot portraits with" applies only to rangefinders, I suppose. </p>
<p>Filter size is a main difference. And also the fact that it's easier to set your preferred aperture and shutter speed on a CF lens than on a C lens.</p>