I live in Michigan with Moscow grey skies most of the time ... plus about 75% of my M shooting is at near-night or indoors I like the look of the M9 files @ 640 and did so with the M8 also. If I could have that look @ 1250 I'd be a happy puppy. 160 seems to start feeling a bit "digital" to my eye ... but not all that bad if I need to go there with the 0.95. But that is neither here nor there, and just personal preference.The m9 s are my go to system ..20k images year mostly street. Agree with Marc on the evolution of the product line. Better Iso performance...they are close but the loss of DR and color fidelity is noticeable even if noise is correctible . Focus confirmation would help especially in low light situations with the fast glass...not sure this is possible using today s technology. Weather sealing for sure. An all day battery would be nice.
Surprised about the comment about ISO 160 as I struggle with getting the most DR possible ... Florida light. I went to 160 for everything on the m8 and have stuck with it. What am I missing.
I only move up when I get below f2.8 and 1/250. Florida is bright easy to shoot f5.6 until dusk.
My biggest wish is to stabilize some of this digital gear and get off the bank busting upgrade cycle. The M10 would have to offer considerable benefits over the M9 to spend the money. I feel my gear box is well balanced right now with the M9 rangefinder, S2P for mobile DSLR type work (in concert with a Sony A900 back-up), and the H4D/60 for commercial assignments requiring specialized applications like view camera work, fabric shoots, or very large files. My hope would be that better ISO performance would be a firmware upgrade for the M9s ...like Hasselblad did for their existing backs.
-Marc