I have read this, but not experienced it. For me, the AF is incredible, I have to say. But then I'm coming from a background of MF film photography, then single point AF, rather than with much more recent 'sports' cameras with the very best AF systems. So for me that would possibly be pearls before swine. I must say, I don't pay much attention to internet reviews, comparisons etc, because I'm perfectly happy with my camera. I'm able to get a very high success rate in terms of focussing, and eye AF is just amazing, the one tool that the Z6 gives me that previous cameras haven't. I often shoot in very demanding situations, with subjects moving around all over the place, often in very poor light, so having an AF system that is much better than what I could do, is a real boon.
So when I read about people complaining about/criticising the AF systems of X, Y or Z camera, I must say I find it somewhat bemusing. I totally accept that others' experiences are very different from mine, and that they have different technical needs. But I am left wondering if people are over-reliant on the technology, and if human skill is being replaced by 'AI'. I do think that the technical standard of sports photography has improved a lot with the modern digital technology, and new AF systems must be contributing to that. So I'm all 'for' improvements in tech.
You see, I've shot 'motorsports' with a D600 with focus tracking AF, and found it absolutely fine. I accept my experience is very limited here. And the D600 is not renowned as a great camera for AF. My Z6 is much better in that regard. So I suppose my point is that I feel 'if this is good enough, excellent even, just how good are the modern systems??!' with some incredulity. I am not criticising any individual here, but I also cannot help wondering if there's an element of bad workmen blaming tools etc. I'm sure there is. But I do like to have some degree of 'control' over my images, and that includes focussing. I don't want the camera taking over from me, because then any genuine creativity is lost.