I will have to recommend the Leica Summilux R80/1.4 as a viable substitute for the Summilux M 75. I have had the Contax Zeiss 85/1.4 and numerous portrait teles over the years but the R80 is something else if portraits is your game.
I have almost reluctantly grown to like it - enough that I am about to pick up an A7 for it. At the moment I am using it on APS-C but find that a bit crippling considering I am sporting a slow-ish camera.
