People balked at me saying the Z6/7 were lacking features like vertical grip, exposure/drive control and dual cards merely because Nikon's short-term strategy is clearly to strip features and use their re-introduction as selling points for the next cameras . . . and here we are with Nikon highlighting dual cards and vertical grip as major selling points for the next Zs. 
Nikon is really gonna blow minds when the next gen Z includes revolutionary new controls for exposure and drive modes. 
I continue waiting on Z mount to receive full-featured cameras that aren't cannibalized for market strategies. I wish the staff Nikon have in camera development had half the confidence in Nikon's brand as their lens people do. They clearly think marketing cannibalized features is their only path to selling enough units.
I think there is no need to go into conspiracy theories or find evil motives regarding why the products have certain features or not. The second card slot, second image processor, and vertical grip all add to the cost and size of the product, and especially with the vertical grip, how much is left of the main attraction of mirrorless which is smaller and lighter, but high quality cameras? They are still smaller and lighter but the difference goes down as features are added.
I think Nikon have a very good grasp of camera design from the point of view of usability and ergonomics. Some manufacturers cram in a lot of physical controls in the smaller surface of the mirrrorless camera, but then if you have long and thick fingers, it becomes more difficult to use those buttons. Nikon went with intermediate size of camera body, well-designed grip, and slightly reduced number of physical controls (compared to mid to high-end DSLRs). I think the designs are well thought-out and e.g. glove users will appreciate that the buttons are large and there is clear space between them. Yes, it means there are fewer custom function buttons and maybe some control has to be accessed via menu, but I think the most important controls are there. If they add more buttons without making the camera of larger size, they become harder to access.
For me the decisive edge that makes me buy into the Z system hasn't really happened yet, but the camera bodies seem to be there already. I'm used to medium telephoto primes and tilt/shift lenses which are absent in the Z lineup, but if I consider Z an addendum to my current existing DSLR system and don't try to make it an all-purpose setup, then there should not be any problem. I could use it for portraits, landscape, and travel, for example, and general short focal length work. The lenses for that are already there. There is just no travel to speak of. ;-)
In the II generation cameras, I think the most important improvement is improved AF (eye focusing and generally autofocus in low light). In my brief sessions testing the Z7, I mostly tried it for indoor portraits and it would sometimes nail the focus and sometimes miss completely, and I couldn't really see what was going wrong. The image quality (when in focus) was superb with the Z 50/1.8. I hope this has been rectified in the II models (Nikon say "superior subject acquisition" which should be exactly the problem I'm talking about) and if it is, then the cameras probably can work for me. However, I had also issues with what the EVF displayed and how the shots came out, and that's another area which I need to evaluate. I'm so used to optical viewfinders that if I photograph a living person with an EVF, I don't seem to get the images I thought I was capturing, and this is something of a critical area for me. With OVF I know how to shoot and get the expressions I am trying to get.
However, the excellent optics nonetheless make the Z system attractive. I just need to work out my issues with the viewfinder if I want to ride along, or elect to use it for tasks that don't require the viewfinder.
