let me add a few comments
hopefully my pictures will show up (or in lieu of simply follow the links)
the first is a picture of my Contax II and IIa together
the second is a picture of my Contax II beside the Russian equivalent a Kiev 4
it is the Kiev 4 which is the same as the Contax II
the Contax IIa has the 50mm Sonnar f1.5 the Contax II has the uncoated 50mm Sonnar f2
the Kiev 4 has the Jupiter 12
they are beautiful cameras but prone to mechanical problems in particular the shutter
I purchased my Contax II on ebay and had it CLA'd
worked great but one year later the shutter ribbons gave way
the Contax IIa was my father's camera so I have an emotional attachment to it
I know my father had it CLA'd while he owned it
and I also had to have it CLA'd because the shutter speeds were off
it worked great for many years
but now the mirror in the rangefinder has appeared to come loose, so that needs to be repaired
have never owned a Leica, and only shot "simple" rangefinders aside from these
but I personally always found it easier to shoot with an SLR, never really took to an RF
https://flic.kr/p/6o2FeU
https://flic.kr/p/6o2FeU