Nikon Z 24-70mm f/2.8 S vs Nikon Z 24-70mm f/4 S
Before we compare the Nikon Z 24-70mm f/2.8 S to other 24-70mm F-mount lenses, let’s see how it does when compared to its smaller brother, the Z 24-70mm f/4 S. Let’s start from 24mm:
For an inexpensive “kit” zoom lens, the Nikon Z 24-70mm f/4 S shows amazing results. It is almost as sharp as its big brother in the center frame, but definitely loses out in the corners.
At 35mm, both lenses do really well at f/4. However, once stopped down to f/5.6, the Nikon Z 24-70mm f/2.8 S shows visibly better corner performance in comparison.
Once zoomed in to 50mm, both lenses are practically identical in sharpness in the center frame, but the 24-70mm f/2.8 is still noticeably better in the corners.
And lastly at 70mm, we can see that the Nikon Z 24-70mm f/2.8 S shows far better corner results wide open. The Nikon Z 24-70mm f/4 S only catches up when stopped down to f/8.
Overall, the Nikon Z 24-70mm f/4 S stood its ground extremely well, especially considering that it is bundled as a kit lens with the Z6 and Z7 bodies. However, the Nikon Z 24-70mm f/2.8 S is still a level above it, especially when it comes to consistency of its performance across the frame.

Nikon Z 24-70mm f/2.8 S vs Nikon 24-70mm f/2.8E VR
To understand how amazing the sharpness of the Nikon Z 24-70mm f/2.8 S is, let’s go ahead and compare it to one of the best 24-70mm lenses on the market, the Nikon 24-70mm f/2.8E VR. Here are both lenses at 24mm:
We can clearly see that the new Nikon Z 24-70mm f/2.8 S is significantly better compared to its F mount version in terms of not only center sharpness at most apertures, but also when it comes to extreme corners. In fact, at 24mm, the new 24-70mm f/2.8 S in the corners is optically superior to every Nikon F wide-angle prime lens I have tested so far!
Once again, the center and the corner performance look incredible on the Nikon Z 24-70mm f/2.8 S at 35mm – there is simply no comparison.
The wide open performance of the Z lens diminishes a little when zoomed in to 50mm, but once stopped down to f/4, the sharpness comes right back. Corners get a little bit weaker, but still substantially better than those of the Nikon 24-70mm f/2.8E VR.
Lastly at 70mm, the lens once again demonstrates superb center sharpness at f/4 and smaller apertures in the center of the frame, and although the corners get a little bit weaker compared to other focal lengths, they are still significantly better than those of the 24-70mm f/2.8E VR.

Nikon Z 24-70mm f/2.8 S vs Nikon 24-70mm f/2.8G
What about the older Nikon 24-70mm f/2.8G? Let’s see how these lenses compare at 24mm:
Although the Nikon 24-70mm f/2.8G is stellar in the center of the frame, it does so in expense of its corner performance, thanks to its heavy field curvature. As you can see, the lens does extremely poorly in the corners, and the only way to improve them is to focus on them, which will obviously reverse the effect and impact center sharpness. There is simply no comparison here – the Z mount version is drastically better.
We can observe similar behavior at 35mm. Although the effect of field curvature is reduced on the 24-70mm f/2.8G, the Z mount version is still noticeably better, especially in the corners.
At 50mm, the Nikon Z 24-70mm f/2.8 S loses in center sharpness at f/2.8, but once stopped down, it quickly outperforms the G version at every aperture.
Finally, with both lenses zoomed to 70mm, we can see that the 24-70mm f/2.8G looks great in the center, but still loses out big time in the mid-frame and the corners. The Nikon Z 24-70mm f/2.8 S is clearly better in comparison.

Nikon Z 24-70mm f/2.8 S vs Tamron 24-70mm f/2.8 VC G2
What about third party lens options? The Tamron SP 24-70mm f/2.8 Di VC USD G2 is quite a popular lens among both Nikon and Canon shooters, so let’s see how it performs at different focal lengths:
At 24mm, the Nikon Z 24-70mm f/2.8 S shows its dominance at every aperture and part of the frame – it is significantly better.
Both lenses do equally well at f/2.8 when zoomed in to 35mm, but that’s only in the center of the frame. As you can see, the Tamron 24-70mm f/2.8 G2 suffers quite a bit in the corners and only recovers a little at f/5.6. The Nikon Z 24-70mm f/2.8 S is far better in comparison, even at f/2.8!
Things get even worse for Tamron at 50mm. Here, we can observe that while it does well in the center, its corners look far worse in comparison. This is due to the same field curvature problem that exists on the Nikon 24-70mm f/2.8G, where good center sharpness comes at the expense of the corners.
The situation does not change much for Tamron at 70mm either. Although it does a little bit better in the center frame, its mid-frame and corner performance are weak in comparison and it really does not improve much even when stopped down. The Nikon Z 24-70mm f/2.8 S, on the other hand, still shows remarkable performance, especially when stopped down to f/5.6.

Nikon Z 24-70mm f/2.8 S vs Tokina AT-X 24-70mm f/2.8 PRO FX
One of my favorite 24-70mm lenses is the Tokina AT-X 24-70mm f/2.8 PRO FX. Even though it is a heavy lens with an old barrel design, and it often suffers from lens variation and focusing issues, it is one of the best-performing 24-70mm lenses for the Nikon F mount out there. It is a lens with superb value for landscape and architectural photographers, because it only costs $899 and it does extremely well when stopped down. Let’s take a look at how it compares to the Nikon Z 24-70mm f/2.8 S at different focal lengths, starting at 24mm:
No question, the Tokina AT-X 24-70mm f/2.8 PRO FX definitely looks much worse than the Z 24-70mm f/2.8 S wide open. However, once stopped down to f/4, it takes off big time and matches the Z mount in center sharpness and even does a bit better at f/5.6. If we choose the best overall performer though, the Nikon Z 24-70mm f/2.8 S is still noticeably better in the mid-frame and the corners, no question there.
Zoomed to 35mm, we can see a similar situation with Tokina starting out weaker and getting much better at f/4 and smaller apertures. Still, the Nikon Z 24-70mm f/2.8 S shows its versatility by outperforming Tamron at the edges of the frame at every aperture.
Once you get to 50mm, the Nikon Z 24-70mm shows visibly better overall results, while the Tokina starts to suffer from field curvature issues. Here, you can see how big of a difference there is in corner sharpness between the two lenses.
Unfortunately, the Tokina 24-70mm doesn’t do very well at 70mm. As you can see, the Nikon Z 24-70mm is significantly better at every part of the frame and aperture.

Overall, the Nikon Z 24-70mm f/2.8 S proved to be a stellar performer. Based on the comparisons presented on this page, we can conclude that it is the best 24-70mm lens Nikon has ever produced, period. I have not yet had a chance to test Canon’s RF 24-70mm f/2.8L IS USM (no high resolution Canon body in existence yet), but I suspect it is going to be the only true competitor to this lens out there.