Just from a logical point of view, looking at both cameras side by side, in-person and in technical details, the rangefinder in the M9 is exactly the same as the rangefinder in the M8. Exact same EBL, exact same magnification, exact same physical baselength, exact same eye relief, exact same size RF patch and exact same color/polarization of the VF window and RF patch.
The ONLY difference between the two are the framelines, which we know don't really do anything. Cover up the frameline illumination window and the finders are identical. You can swap them between cameras and never know.
So, Leica's marketing strategy of saying that the M9 is easier to focus is just that and I don't believe it at all. I use them side by side on a daily basis and there is zero difference between the two.
Leica is a clever marketing firm though. Clever enough to get us to pay $5200-7000 for a camera body alone. I don't believe a lot of what Leica says because they are a business, after all. In it to make a profit.
If they can list the exact same specifications from the exact same materials on one particular assembly and say that one model is easier to use than another in spite of their specifications being exactly the same, then that "easier focusing" ploy should be viewed as suspect.
Don't get me wrong, the M9 is a fantastic camera, I love mine, it's just that between the two, there is no difference in focusing.
Phil Forrest