I prefer a Leitz lens which is a result of hand calculation optimization not computer. An Genius sits on a table and works 10 hours a day for 2 or more years and when working with mathematics , he develops new mathematical view angles , formulas.
An computer can generate a lens but it cant generate itselves rules. Why Leica expensive , because they developed all better chemistry, mathematics , physics by themselves , they did not buy a 40 dollar research article , carry in to software and than generate the lenses as much as good as article.

Dont forget , older 60 years old Leitz lenses have two times more resolution at the corner than latest Summicron. Bokeh is not important , texture , degrades and colors are important. You cant get same color with canada leicas. I really hate everything about latest Leica images.

Dont waste your hard earned money to tourist traps , buy a IIF with Summar , no other lens can beat it.

Umut