I captured this image shortly after acquiring a Nikon Z 6III and beginning to field test it. To be honest I had quite low expectations for the Z 6III, largely owing to how much of an advance the Z 9 was over the Z 6III's precursor (the Z 6II). Boy, was I ever wrong! I REALLY like the Z 6III as a wildlife camera and for me it occupies almost the same performance niche in still photography as the D6. And, in some ways it's considerably BETTER than the D6.
I know some will think I'm a bit nuts in comparing the Z 6III to the D6 (from a pure "performance in the field" perspective) and claiming they occupy a similar niche for still wildlife photographers. But when you stop and think about it I think the comparison is valid. Based on my own testing it appears that the ISO performance of the Z 6III is very similar to that of the D6 (and from a noise perspective it's about 1.3 to 1.5 stops "better" than a Z 9 or Z 8). And the Z 6III is as responsive and fast as a D6 (and certainly faster in frame rate).
Just how does the Z 6III BEAT the D6? Well...the AF is excellent and, at least IMHO, considerably better than that of the D6. The Z 6III also has a faster frame rate (along with virtually no shutter lag), and is MUCH smaller and lighter than the D6 (those wanting to ADD weight to the Z 6III to better balance super-telephoto lenses - and add vertical controls and longer battery life - can add the MB-N14 battery grip to the Z 6III). And then, of course, there are all the advantages inherent with the Z 6III being a mirrorless camera, including a much more information-loaded viewfinder, dramatically better video, more accurate AF with WAY BETTER tracking, better teleconverter performance (even when shooting adapted F-mount lenses), dramatically better VR, yada, yada, yada. Additionally, the Z 6III is a whole lot cheaper than the D6.
Of course, no one in their right mind would argue that the Z 6III is as durable or robust as a D6...I have no doubt that some of the things you could put a D6 successfully through (like shooting at -30C) would be beyond the capabilities of a Z 6III - if you do that kind of shooting a D6 (or possibly a Z 9) would very likely work better for you.
If we return to this shot for a second it's easy to see how the Z 6III would outperform a D6 in this instance. This image was hand-held and captured at 1/40s (using a 600mm lens). I don't know about you, but successfully hand-holding a D6 with a 600mm VR lens while shooting at 1/40s (and getting a tack-sharp shot) just never happened for me. For wildlife photographers hand-holding big lenses...well...the VR of the Z 6III makes it dramatically more "usable" than a D6 for many.
Anyway...I readily admit I'm already a big fan of the Z 6III and I look forward to taking it with me during even my most "serious" wildlife shoots and expeditions.