Maybe you just got a good copy. Check out the aggregated test scores provided by JohnNEX here on dpreview. They show that there is not a significant difference between the 24-70/4 and 24-105/4. In particular, while the 24-105/4 may be slightly better overall, it is slightly worse at all apertures at 50mm.
The Nikon Z 24-70mm f/2.8 S is no different. It has an impressive set of handling features, much better than those of the Z 24-70mm f/4 S. Specifically: The 24-70mm f/2.8 has three control rings (zoom, focus, and custom) while the 24-70mm f/4 has two (zoom, focus) The 24-70mm f/2.8 has an EL display, while the 24-70mm f/4 does not Any of Nikon Z owners upgrade from the f/4 24-70mm to the f/2.8? Did you find it was $$ well spent? I noticed the lens is below $2000 new now. So Compare Nikon NIKKOR Z 24-200mm f 4-6.3 VR Lens vs Nikon NIKKOR Z 70-200mm f 2.8 VR S Lens vs Nikon NIKKOR Z 24-70mm f 4 S Lens Press ‎ ↵ Enter ‎ for Accessibility for blind people who use screen readers . 91 406 366 117 278 139 470 466