astrobuoy
Established
I shoot with both Zeiss and Leica glass, and I think my Pentax lenses truly stand toe to toe. Of course each has its own look and characteristics, but I personally couldn't say that the Pentax is "worse" or poorer in any regard.
That said, if you want the Zeiss or Leica look in a (relatively) compact SLR, I would suggest a Contax Aria with the Planar 50mm f/1.4, or perhaps a Leica R5 with a Summicron 50mm f/2.
The MX is quite small, so finding something with comparable dimensions will be a challenge. Size-wise perhaps an Olympus OM4 or OM2 with a 50mm f/1.8, though I don't love the rendering personally. The OM 50mm f/2 Macro has been claimed to have "Leica-like" rendering, but it can be expensive, and also slightly larger than the others mentioned here.
That said, if you want the Zeiss or Leica look in a (relatively) compact SLR, I would suggest a Contax Aria with the Planar 50mm f/1.4, or perhaps a Leica R5 with a Summicron 50mm f/2.
The MX is quite small, so finding something with comparable dimensions will be a challenge. Size-wise perhaps an Olympus OM4 or OM2 with a 50mm f/1.8, though I don't love the rendering personally. The OM 50mm f/2 Macro has been claimed to have "Leica-like" rendering, but it can be expensive, and also slightly larger than the others mentioned here.

