I shot the Leica 75mm f/2 APO-Summicron-M ASPH extensively on my trip. At about $3795 it is medium-priced as Leica M lenses go, but a real jewel in size and weight and handling. A keeper for the long term on Leica M and (to be proven out) mirrorless.
Its 90mm f/2 APO sibling is just slightly enlarged in size and weight, but something about 75mm seems just right to me for the way I shoot.
I owned the 75/2 APO for a couple of years then sold it, because M9 rangefinder focusing was a frustrating hit-and-miss affair.
But on the Leica M Typ 240 with EVF, the experience is wholly different: things snap into focus crisply, much more clearly than with most Leica M lenses (some are too low in contrast wide open and the slower lenses have too much depth of field to discriminate focus easily). The 75/2 APO has that blend of high contrast wide open, f/2 aperture, and moderate telephoto separation that make focusing enjoyable.
Still, the focus throw of the 75/2 APO is a bit light: I found that merely brushing my fingers off the focusing ring could slightly tweak the focus, so I learned to take care as I achieved focus and re-gripped the lens for shooting. Possibly Leica could stiffen up the focus upon request (not sure).
The soon-to-arrive Sony A7R raises an interesting question: might the 75mm f/2 APO be an ideal match for the A7R? That is a question I will be putting to the test. It involves a lens adapter and the sensor+optic interaction. I expect very high quality results, but it is not a given. But it would be delightful to see the full 36 megapixels utilized.
Not every day yields beautiful light. After a week of gorgeous weather, a storm front brought its grayish haze to the area. I shot this stitched panorama as I was leaving the Lee Vining / Mono Lake area, forced the long way home due to closures of Hwy 120, Hwy 108 and Hwy 4 over the Sierra; I took Hwy 89 over Carson Pass.