Acc. to blog.kasson.com, most Hasselblad H lenses are good on the 5.3 um sensor of the X1D and GFX if stopped down by +/- 2 stops but at open aperture corner-to-corner they are no match for the native Hasselblad XCD or Fuji GF lenses. With the future 100 MP 3.76 um sensors, that difference in quality will be even more apparent.
I looked at Jim Kasson's site. The differences in "image quality" (let's be clearer and say "resolution and contrast", okay? because there is no measure for image quality) seem to be within 5%. For a 50 Mpixel image rendered to an 11x14 or even 22x28 inch print, that difference is likely invisible to the eye and far less important than the content and rendering qualities. I guess if you're making 36x48 inch prints, or larger, it starts to be a factor. Never mind 100 Mpixel images.
Once upon a time, I was making a significant percentage of my income from selling prints. Most of the prints I've sold are 6x8 to 11x17 inch image area. The rare sale of a 20"-plus sized print at a much higher price amounted to a miniscule fraction of my income. Objectively, I could get away with a 5 Mpixel, FourThirds format camera for probably 90% of the work I've sold; APS-C and FF at 24 Mpixel is most certainly more than enough. However, I love Medium Format and larger-than-FF sized format for their imaging qualities, and Hasselblad for its lenses.
So I don't think the issues Jim mentions are all that important to me.
An X1D with the 21mm lens, maybe the 120 macro, and adapting my existing V system and even Leica lenses to it, are probably all I'll ever want, if I even want that enough to spend the approx $10-14K needed to acquire it. I saw a couple of X1D bodies going secondhand for $4000 plus or minus ... I might just start with that only and a mount adapter, see where it takes me. I can pay for it by selling my WATE, which I don't use enough to warrant its price.
Hmm. I shouldn't have looked at this thread, ya know? Sigh...
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