Is the focus on the same spot? Feels a little bit like the focus is a little more behind the horse on the left. But apart from that, hard to tell them apart. The right one has slightly warmer highlights, but only ever so slightly. Level of detail feels almost exactly alike, if you take into account that they are focused 1-2 meters apart.
In short... I wouldn't notice if you shot with one or the other. So down to handling and compatibility with other gear
The one on the left is better tight, and the one on the right is better wide. But to be honest, I wouldn't accept either one of them. Neither looks good enough. What camera is this?
Both shots above were cropped 500% (and more or less backlit)
Then I made a few other clips at 300mm: the sony full open and the nikkr at 5.6:
These shots are 4K uncropped at 300mm
I left the IS on the sony lens and that was not a good idea. Focussed on the mill.
I must do something wrong, or the Nikkor is still a very good lens I can't see much difference on my UHD screen.
The Nikkor is heavy (2200 gram vs 1600 gram sony) but has an F4.5, not parfocal and max 300mm
sony is much lighter, 5.6 parfocal and goes to 400mm
And lens fits well, no flimsy adaptors. But I am still in doubt.