I only have one to thing to say about this: Mandler was a GOD of lens design and the resulting character.
(And I'm willing fight with anybody who disagrees.) :ROTFL:
Computers and aspheric elements can render more perfect optical performance, but perfection in optical performance for creative imaging is significantly over-rated --- lest you have a specific need for it, and I submit ultra-wide-aperture/shallow DOF imaging is not going to require that need... Any of us present or past Leica photographers with a predominant amount of gray hair, know and respect the capabilities of Mandler lenses. If I were to resurge to Leica M, I would immediately buy a 28/2 Cron (it drew exceptionally well, but not certain it was a Mandler lens -- had to at least be one of his contemporaries
), pre-asph 50 and 75 Summilux's, and probably a 21/2.8 Elmarit as well; and in R I wouldn't even consider a body unless I could also immediately buy a 19/2.8 and an 80/1.4.
PS: We used to refer the specific Mandler-style look as "juice"