Since turning pro in the early 1970s, I've always used a combo of Leicas (21/28/35/50mm lenses) and Nikons (14/24/35/105/80-200/300,2.8/400,2.8) and in the 70's had an M2R and two M4s. I still have the M4s and lenses - all Crons except the 21/2.8 - and have used the lenses on an M8 and an M9, and they work great with the digital bodies. While the newer asph lenses are sharp (maybe even a bit sharper), they also - to me anyway - have a lack of character and tend to flatten out perspectives for the sake of a tiny bit less distortion. I used a modern 21/2.8 asph Elmar on the M8 to get the 28mm with the M8's APS-H slightly cropped sensor, but reverted back to my older 21 for what was a much better looking rendering, imho.
It's a myth that the older lenses don't have enough resolution to support today's digital sensors. The equivalent resolution of good 355 film is generally accepted to be the equal of 24 megapixel sensors. Sensors have much more dynamic range than film. I also use lenses from the 70s and 80s on my new digital Nikons (7200, 750, 850) and I think they look better than the new lenses. Even my 300/2.8 is from the late 80s. Newest Nikon lens I have is the Gen1 400/2.8 from 1995. I just like the look of old glass, I guess.
Unless you're really hankering to have the auto-focus capability, and/or a 28lux, If I was in your position I'd be looking for a lightly used M240 M-P to use with the glass you already have. I bought my Q specifically for covering the presidential campaign trail the last half of 2015 through 2016, and wanted the fast AF and fast f-stop for my main around the neck camera, which has always been a Leica with a 28mm on it. I've also found the Q to be an amazing camera for a lot of other stuff I shoot, and the focus peeking is great for manual focusing. I use it a lot for location editorial portraits with multiple strobe set ups, and for studio sessions with and without strobes.
Edited by beez, 14 March 2018 - 22:38.