I have never owned/shot the contax, but it would be my pic. A number of years ago I had some extra money, bought both a p67 and pentax 645 with a couple lenses for each. I did detailed side by side shots, same film same spot, tripod, etc, and found that with as big an enlargement I could make on my d2, the 645 outperformed the p67. I had assumed that the bigger negative would be better, but turns out it wasnt the case. Kept the 645, ditched the 67. Negative size is just one part of the equation.