I have had a look at the Rollei Hy6 - man - that camera looks cool, but it also makes the Contax look cheap. Also very few on the used market. I guess the camera is not that old.
For the Pentax - I already know that AF Mamiya work only is stop-down mode metering mode - how about the Pentax?
For the MLU with Pentax - would you say one really does not need it even with 200 - 300mm lenses on tripod with exposure about 1/2s - 1/30s ? That would be rather surprising. As far as I know even with 35mm cameras this shutter speeds are sensitive to the additional shake induced by the mirror. Indeed - the point about the camera weight applies (the heavier the less shaky)
In general - what lenses from Mamiya, Pentax and Contax do you consider the best within the lens line-ups?