Marc,
I agree with your observations that the S series of lenses are by far the best out there. The ability to use other brands of lenses opens up the possibilities for specialty lenses and lower cost alternatives till one can save up the funds to purchase one of those gems. While the Hassey 120 is not as crisp as the 120 S, it does put up a good fight and the cost of mine was $300 or one S hood and lens cap :). The 35 S is scary sharp, in the comparison with the Hassey 40 FLE, what I first thought was noise artifact in the shot actually was the texture of the plastic. That was pixel peeping, at normal display settings, they did not appear that different. Each image held it’s own ground, but side by side you could tell the difference.
In the end, it is nice to be able to entertain other options while I wait for the supply chain to open up for S lenses. Sort of like the Zeiss and CV lenses for the M9, lower cost and a steady supply give users a lot more options.