Originally Posted by Keith
It's interesting that the M240 has offered little over the M9 aside from video (who cares) and better high ISO performance. As said above Leica will need to lift their game if they want to maintain station against the tide of new full frame compacts that can mount their lenses.
I had a chance to try out the M240 again very recently, it had been over a year since I first handled one.
For me, the big thing that the M240 has over both the M9 and the A7 is responsiveness: the shutter response is close to what I get with the Olympus E-M1 and E-1, or the R8 and Nikon F film SLRs. The A7 is closer to the FM2 with MD-12 fitted, the M9 is slower responding.
In terms of output image qualities (color, tonal range, etc), it's different from the M9 or A7 but neither worse nor better. It produces less moiré at the limits than the M9 and about the same detailing as the A7 (a little more or less, I didn't shoot any certified resolution targets). The colors it produces in its raw files are just as malleable as the M9 or A7 raw files.
While it might do better with some wide RF lenses than the A7 or M9, I can only test with the lenses I have (Color Skopar 21, 28, 35 vs Elmarit R 19, 24, 35). I didn't have time to do any exhaustive testing, but my impression with the Color Skopar 28mm was that it color-shifts less on the M240 than it does on the M9. I haven't used that lens on the A7 yet; I prefer the Elmarit-R 24mm for the A7.
None of these cameras are perfect; no camera is. I've been very pleased with the M9 for use with the Color-Skopar 35/2.5 and Nokton 50/1.5 ASPH (LTM), and more than very pleased with the A7 for use with all of my R lenses.