Upload & Sell: Off
now take this with a grain of salt since I own neither an M9 nor 5Dii, but I acquired raw files from both cameras and compared. and not just random shots either; lab shots where focus was walked through and the best samples were provided from both cameras. setup one was 5Dii with 50MP. setup two was M9 with v5 summicron 50.
understand 50MP is a sharper lens, and much higher contrast. I have seen on film that it is beyond what the old (v4/5 formula is from 76) summicron formulation can do, especially at lab focus distance.
but the M9 raws were WAY sharper than 5Dii using ACR. and nothing I could do in PS could make up that difference. when I downsize to web dimensions, 5D looked sharper because 50MP has such high contrast.
POP or "sharpness" from websize images almost all comes from sharpening/contrast enhancement and the contrast of the lens at the relevant frequencies FOR THE ENLARGEMENT.
I have a good example of such things happening. I owned a while ago a ZM50 Planar, for Leica, and a Dual Range Summicron, and a Zuiko 50/3.5 Macro. I have seen measured MTFs for all 3; DR has highest extinction frequncy, ZM highest "global" contrast and Zuiko best at 40 lp/mm. I shot all 3 on the same roll of Delta 100 developed in Xtol 1:1 and compared my perceived "sharpness"
2. zm planar
3. dr summicron
on downsized scan (multistep sharpening)
1. planar (perception of fine detail)
2. zuiko (lots of "crunch", my favorite but not "sharpest")
3. dr summicron
examined with loupe
1. dr summicron
which was "sharpest"? if you enlarge enough, DR summicron. but I sold it quickly, because I realized that even at 11x14 (the largest I can do with my scanner with high quality) it looked the worst by a lot. I sold the ZM planar shortly after, when I got other lenses that made me question value of ZM planar and used that money to buy my own 50MP.
post processing is very individual and most people are bad at it (as they are indeed bad at most things). if you are seriously considering purchase, track down some raw files from a lens you actually intend to purchase and use with it and process it yourself and compare. if you are really lucky, you might get someone with good PP flow to send you a PSD with their method on it so you can see what you could get.
btw I hate the word "pop" when describing images so much. funny enough the image I saw with the most of that had missed focus lmao.