[JJ_SO]

      Firstly I just wanted to give a simple opinion of what I found trying the Z6's EVF ........ as I found it and without any preconceptions ....... I wasn't posting to change anybody's experience/pleasure or personal opinions ........ 

  I will reply to your points with brevity as there are many.

  The EVF plus points ....... with screen coverage being 100% for the D500 and 97% D750                                 .......   equal.
                   .......  ND filters, I have a 9 stop ..... yeah dark OVF   ...so you have to shoot LV from the rear screen ..... +1
                    ...... AF accuracy remains a weak point for TPM's DSLR lenses and we all know about lens calibrating! ....  +1
                 ........ I suppose corrections play a role when shooting ..... but very little.                                          ........+ 1

    The EVF minus points.



                  ..... battery life .......                                           big DSLR advantage ......                   .                 ....... +1 
                  ..... yeah a nice clear screen                                  ""    ""          ""                                                       ........+ 1
               ........ the D500 shows       "flicker"      in the OVF when there are flickering LEDS.                              ........equal
               ....... there is none lag in the DSLR   (not including  LV)                                                    DSLR             technical win
                ....... AF consistency will always be better with ML                                                           ML              technical win 

   So ML has many advantages now and will continue to pull in front of the DSLR and I can see quite clearly these advantages are good for what your doing .... especially when it come to nailing focus with a nice large aperture Sigma.

   So, the situation is one of suitability of a camera to the shooter, if it's an "always bright finder" with corrections, super accurate focus and all the other things you stated, ML out ways the shortfalls that DSLRs inherently have, plus the great improvements of shorter registration distance, it's certainly the way forward!....... 

...... but, that's not where I am, I need good battery life, fast AF-C and a OVF where I can see clearly all the gestures of the bird I'm waiting on.

Maybe I'm even biased ...... through long formed habits .... I've been shooting DSLRs for fifty years

We both forgot something simple: You always can look through an OVF without switching anything ON.

I think, if you'd shoot once with one of the latest Sonys and observe how the focus point is glued to the bird - in real time and while shooting 10+fps bursts - the bias could melt quickly - or remain.

To me, the EVFs vary: the Fujis and Sonys before really sucked, the one of the 1V 2 (the small father of the Z 7) as well, but with operational focus points - just only for genuine lenses. The one of the P7800 is like 5-8 year old tech. The Z 7 is the first EVF I use and found it equal to the D850 (except in DX mode, as the EVF doesn't tell me about the crop, except with a tiny icon - it shows the same area. 

As for the cluttered EVF, I need to correct myself: It's the LCD which is full of icons and signals, the EVF is clean.