More food for thought:
Erwin Puts does write that overall the Hexar 35/2 is better than Leica's 35/2 pre-Asph (Cron IV).
Chasseur d' Images #240 published earlier reports on the Hexar and Leica lenses together. They rate the Hexar 35/2 highly. Four stars for "Note technique" and "Cote d'amour" -- but they rate the Leica Summicron 35/2 Asph higher: five stars on both counts. (Interestingly, they rate the Hexar 28/2.8 higher than the new Elmarit 28/2.8.) See pages 176 and 177.
Erwin Puts views on lenses better than Leica's, e.g. Canon 300 f2.8 IS, Konica Hexanon 50 f2, Hexanon 35 f2, Voigtlander Nokton 50 f1.5!
Stephen Gandy from CameraQuest: An ODD thing about these lenses is that if you put them side by side their Leica equivalents, the Konica lenses appear to be the better made with heavier construction! OK, I know it's Leica heresy even to suggest such a possibility, but try putting the new Konica M lenses side by side current lens offerings from Solms, and draw your own conclusions.
Colin Jago (Auspiscious Dragon): 50mm f2 KM mount - 1999. Very highly regarded.
Robert Hitt: Konica had a peculiar, almost dilettante attitude to lens production. Almost Leica-like in some ways with the limited production runs. Hexanon has always been of the highest quality. During their production heyday years the Hexanon lenses were used by the Japanese Ministry of Industry as the reference standard by which the quality of all other manufacturers' lenses were judged. There are other Japanese companies that make extremely high quality glass in limited quantity that fit Leica, the Y.K. Optical Company that makes the Kobalux lenses comes to mind.
The older Summicon has interesting imaging properties, but has problems with 'valed flare' which can lower contrast over the whole image, and in extreme cases 'halo flare'.