At the recent NYC Photo Expo at the Javits Center there was an entire table filled with Nikon's new Z7 camera. A brief look was enough to know the camera is Nikon's attempt to catch up with the wildly successful Sony line of full frame mirrorless cameras. I wasn't particularly impressed with the Z7; there's little chance I would ever use either the Z7 or any of Sony's cameras for my own work. Both are simply too small and lightweight to be a comfortable fit in my hands. Moreover, for professional work I strongly prefer the DSLR's optical viewfinder over mirrorless cameras' electronic viewfinders.
I'm not really qualified to give a review of the Z7; those interested shoud go to Dpreview's review that fully lists the camera specs and provides a detailed analysis. I'd note in passing that there are only three lenses currently available for the Z7. Other Nikon lenses can be used via an adapter, but this has to negatively impact image quality.
I also saw the Nikon's new 500mm lens (see photo below) on the same table but was disappointed since it was not nearly as compact and lightweight as I'd been led to expect.