Thanks again for taking the trouble to make the comparisons, to me it's timely information but it wouldn't have changed my decision on getting the M9.
Simply, I don't own a M8, though your part 1 results were pretty close, I would have chosen M9 because of the FF, this is the single most important consideration of mine. Other enhancements are bonus to me, even the need of using a IR filter is no longer applicable to M9.
I actually would have appreciated more if you have made comparisons based on actual/equivalent focal lengths of these lenses on how the perspective of a 24mm on a M8 yields a different result of an actual 35mm on a FF. That would have been my 2nd most important criterion for waiting and choosing a FF RF, it so happens that it's Leica which leads the market in introducing the first FF RF allowing the use of all fine Leitz optics. If Epson or Nikon rushed out a FF RF which accepts leica optics, I would have chosen them, no question asked. That would have been my 3rd most important criterion.
I leave out the cost of owning the Leica as it's simply not possible today to benchmark it against an alternative. I made decision based on value, not cost. A decision choosing the right tool for my shooting style, an inconspicuous camera and it happens to be a Leica.
Thanks Ng.