No Keith,there is a widespread misapprehension that camera X or Y has a "sensor that is less noisy" Apart from the fact that the S/N ratio of a sensor is related to the pixel size (which is not the same as the pixel density btw), there is no significant difference between sensors of the same type. The differences lie in the way that or degree that noisereduction is applied in the camera. The M8 sensor is a relatively quiet one, as the output is quite high, hence ISO 160. But the camera is of necessity built up from discrete electronic components, as the series was too small to warrant a dedicated processor chip, so the computing power is limited, which limits the processing of the file in-camera. This is assuming Leica would deem the quality of the processed file good enough in the first place. So it falls to the user to make these corrections. I think the M9, which will use the new Maestro chip developed for the S2, but destined for the R10 and M9 etc., which wil not just multiply the processing capability of the camera, but enlarge it by magnitudes, will profit by having far more sophisticated noise-reduction programs built in. But the sensor itself will be just as noisy, or even noisier, if Leica ups the pixel-count, which seems likely.
For the time being, with the M8 and many medium format backs as well, for instance, we are stuck with learning to use our powerful PCs and Macs to get the results we want. What I tried to point out is that I do not see any philosophical difference between doing this at the beginning of the process in the camera or halfway in the computer.