[JJ_SO]

What's the point in making FF as compact as APS-C (most of the time) already is? I know you're much more knowledgeable in terms of the equvalencing game than I ever will care to be, but crop calculators aside, what IS the point in

• buying a high res FF sensor and mounting "cheap" lenses in front of it? And by "cheap" I mean South of half the price for a f/2.8 than for it's f/1.4 version
  
• giving up a big plus of a bigger sensor - if shalllow DoF does count as "plus" in the buyers book?
  
• giving up another big plus like high ISO by slow lenses which cosume this advantage?
  

A friend of me with a nice collection of various Fuji bodies and a huge set of lenses recently became also member of the Sony user group. He didn't want to wait for the α7R IV and bought a III. Of course he said "I don't need 60 MP", I say so too but I don't believe any of us both.

Smaller than a Z 7 and even an X-H1, but never as small as a µ 4/3 with a pancake. So why trying to squeeze compactness into something which was not made for being small?

Else than that, he bought 4 lenses. None of them Sony or Zeiss, but all very nice: A Laowa 100 mm 2:1 prime, an Apo-Lanthar 65 mm from Voigtländer and the two new Tamron zooms 17-28-75. Yes it's nice that Sony opened their mount - but they had to, while Nikon and Canon have a ton of legacy glass and their adapters.

The Laowa and Voigtländer being manual focus, the Laowa as usual without EXIF Data and spring diaphragm. Would be a pain to use on a DLSR...

Side note: Apparently the sensors of the α7R IV, GFX100 and X-T3 are children of the same wafer as their pixel width is identical.