This thread reminded me of a fun game from when I was a kid. We would take a coin or a kini, stand it on edge on a board, then hit the board with a hammer to make it jump but not fall over.
So, whether or not a penny will stay standing doesn't really tell much of anything compared to something like the size and shape of a pin-point of light on film...
I would suggest a different kind of penny test. Put the penny flat side down on one of the many inclined surfaces on the Hasselblad. Press the button. Does the penny move? On my 500C, the answer is yes. Especially if you turn the camera sideways and put the penny on one of the surfaces with the winding knob.
OK, not the usual recommendation. However I recently bought the glass 75mm for mine and recently got around to giving it a go. Well it is quite a revelation. A small bit of vignetting but the main picture was sharp on Ars-Imago 320 and FP4. In fact the lens seems to be too good for the Diana.
I shot MF mainly with an RB67 and I got a Mamiya 7 to make my life a little lighter. I didn't think it through, however, and discovered that I cannot get as close with the Mamiya 7 as I did with the RB67. I kept both anyway. Each has its place.
If you prefer 6x7, i'd go with the Mamiya 7 or the Plaubel Makina. I had & used the Pentax 67 & while it worked with short lenses, I could never get sharp negatives with the 200 or 300 even on a tripd with a lens support & the mirror locked up. That focal plane shutter is like a guillotine & loud.