I'm on the waiting list hoping $7450 falls out of the sky between now and when I get the call .
This is a good review on the cameras, if you have not seen it already.
What I noticed was the M Monochrom rendering of the sky was smoother than the M246. You could see less grey levels used by the M246 image.
On first glance, the MM9 appears to give the smoothest gradations at base ISO. However, it’s important to remember that the file’s overall micro-contrast has been softened by the upsizing process, which has the effect of greatly minimizing the visible noise. In reality, files from the MM9 (that have not been upsized) have a nearly identical noise floor as the M240 and M246 cameras.