The GXR / Mount A12 is what I shoot almost exclusively.
The GXR isn't perfect but it handles well and performs beautifully as you say. I don't care that it isn't a rangefinder - the focusing and framing method wasn't central to my interest in RF cameras and lenses in the first place; the compactness of RF cameras, overall simplicity, and particularly the lenses, is what drew me to shooting film RF before I took a long detour shooting nothing but medium format film.
Having moved away from medium format and film simultaneously, what captures my attention is high IQ in small, portable, packages. The GXR almost gets me to where I want to be, but I'd like to use my lens complement on a full frame camera and get their originally intended perspective and other attributes back.
Maybe Ricoh won't go ever take the GXR to the next, logical, step. If not, that'd be a shame. If they don't go there I doubt anyone else will.
Back to the central point of this thread - Leica states they won't make a compact electronic M camera; at this point I still believe there's a good chance another will and that company is Ricoh. Call it $2,000 - $3,000, somewhere in there is the right number for them.
I have to believe that a full frame M camera selling for barely more than a fixed lens APS-C Leica X2 would be of great interest to M lens users. Maybe not of interest to all M lens owners, but of interest to more than enough... and I'm one. Where is the pre-order link?