I fail to understand how this would be preferable to a full-frame mirrorless camera that can use lenses from multiple systems. Having a long mount register, the R system is among the least adaptable to other lenses. If you want painless migration to another system you want to be able to use your existing lenses. R isn't it.
But I didn't ask for that.
And if I was buying into a new R system, why would I want other types of lenses? I didn't buy anything but Nikkors ever since the F came into my life; were I into Leica R, imaginary new or established old, I'd be of the same faithful disposition.
As I wrote, I never personally owned Leica of any type, but as an assistant at one stage, I did print from one or the other of the 21mm lenses in
black/white, and there was a quality there that I never got from anything else. It was not imaginary. In fact, perhaps a bit naughty, but I kept a print from that M3/21mm combo in my portfolio as an example of my printing ability. Many decry the difference between Leica optics and others; having printed from some of them I know the differences are real. I have had them happen to me, with no horse to back in any personal race. Just was. I also, years later, had a client request Cibas from another photographer's Leica shoot. The colour, in this instance, was wonderful too.
There's a funny story related to this concerning Stan Malinowski: he used all sorts of cameras trying to catch the colours on Kodachrome that he saw in the work of Francis Giacobetti. He assumed that they were Leitz optics and so he bought. Then, working for an art director who knew both photographers, he was told that no, Giacobetti used Zeiss... however, I think that was either a diplomatic fib or that the latter changed equipment, for a while later I saw his work in French
PHOTO and he was using Leica 180mm...
The story comes from my memory of Stan's website, which I can no longer open despite finding several links to it in Google. He used to use it under the name modelpix, which still appears under his actual name in Google. Wonders of the new world.
Rob C