I have the 50c back for my V system, might sell it to upgrade to the new one.
Like any gear purchase, it is a highly personal choice and not always apples to apples. I bought the back after I demoed it and found it to have more color range and tonal nuance than my Nikon D810 at the time and it still does over my D850 and Z7, not by a lot but by enough to justify it for what it's special role is.
It is much easier for me to carry a spare and digital back out with me when shooting black and white film for fine art purposes using my Hasselblad system rather than a whole other camera system in addition to the Hasselblads when also needing to satisfy a digital need.
Compared to a Leica M10, it is no contest, the 50MP Hasselblad back's sensor is much larger and again with far greater color and tonal range in actual use, regardless of what the specs say. Of course high ISO is another story but that is not what I use the Hasselblad system for.
I also don't mind the crop factor either, I think many of even the newer CFi lenses I own would be somewhat punished by a full frame square sensor so I am more than fine with it.