What does it make a good camera? I guess the handling and ability to work with a cam in the situation you need it. And the output.
I find myselves in a similar situation, seeing some pics from great artist and wanting to be able to make better pictures with richer colors.
Though questionable is: is it the camera or the processing?
What really surprises me, that nobody really has comparison pics - before spending so much money I would definitely do that.
We could argue, though I don't think an MF camera is that much better in handling then a 35mm dslr to justify the price(more even the other way round for many purposes - my K5 with pancakes handles so incredibly well). So where really the difference should be is output quality, in what ever way that is. Here I just don't get enough information.
As you might say in germany: "Ein Bild sagt mehr als 1000 Worte".
I had a phase one P40+ for try and compared it with my d700 in studio for some beauty shots. Depth of field was a bit narrower in some settings, what made it interesting.Worth 20k? probably not, as grey filter could help to reduce aperture and allow me to get similar results. Colors no noticeable win.
Of course if you zoom in, there is an incredible load of structure and detail. To have a nice pic though it is hardly a factor,except the really big prints of course.
So I guess conclusion: if size matters.
Still I was not able to get a Hasselblad H4d-40 to compare. Colors might be better here?
What I found out in my research is: some guys have P1, some HB. The people I met couldn't really tell the differences. I guess they also better be happy with what they have as they just spend all their savings on it and don't want to question that.
Another thing is of course is reputation, you might get a project because they see you have a hasselblad
For me: I'm ready to spend the money if I can see a clear difference in prints up to A1 size. If not I'm better off waiting for the Nikon announcements.
I guess the more limiting factor with Nikon on FF could be the glass if it comes to resolution and contrast.
So if you find out something special on your journey I'd be happy to hear from you