It's foolish to compare these early seventies rangefinders (fine as they indeed were), with Leicas. Leica is best known for making rangefinder cameras with interchangeable lenses that were expensive (today insanely so), the others in this thread have "normal" lenses solidly built into the camera, so one will be stuck with that focal length (Note that Japan did produce some excellent interchangeable lens RF models, The Nikon SP and Canon VII to name two, but realized circa 1963 that an SLR made more sense for a camera to be used with an extensive choice of lenses).
Those cameras with the f2.8 lenses are worth considering. They are obviously more compact, and tend to be more reliable (those with f1.7 lenses also have a larger and more complex shutter - I've seen tons of them at camera shows and thrift stores with their shutters rusted shut - make sure the shutter works!). One inexpensive fixed lens RF camera I would add to the list is the Ricoh 500G.
BTW - "more elements make a better lens" is not a universal truth. While a good four-element lens will outperform the single meniscus lens, many lenses have more elements in their design to make the lens more versatile, Not sharper. f1.2 lenses are rarely considered to be sharp, even though their designs are quite complicated to squeeze every last bit of light out of the scene. Many zoom lenses are full of elements to achieve their broad zoom range, though zoom lenses, as a class, are generally lower in contrast, lower in sharpness, higher in aberration, higher in distortion, and higher in flare, than prime (one focal length) lenses.
In other cases, a lens manufacturer may need to design a lens with more elements to work around their lack of access to very high index optical glass materials.
This is not to say zoom lenses are bad lenses. However, excellent zoom lenses ARE NOT CHEAP.