Originally posted by Kozlok A different perspective: For my purposes, Pentax autofocus is generally great. I do have a few really amazing shots, in that perfect moment, with amazing light, that missed focus, so end up unusable. From what I gather, Sony's autofocus system set on AFC would have nailed most of those shots and I'd have had a few real winners. This alone has not tempted me to change systems (there are negatives to each system, after all), but it has come very close.
There is that video made the Camera store of a cyclist, that suggests you might be wrong. What did they do different? They had a real photographer use three different cameras, one being a K-1 with a DFA 24-70. They actually used the three cameras to be compared doing the same test, with the same cyclist on the same hill. None of the other reviewers who make such claims have objective side by side tests to prove it. In fact the drunk cyclist test, no other camera had been put through that test so it was completely ridiculous that the reviewers claimed it showed Pentax AF was inferior. It's a sign of incompetent reviewers rather than a cirticism of Pentax.
It gets tiring seeing people constantly claiming Sony AF would have nailed something based on web opinions. As far as I can tell, eye AF may get you something special, but unless you're shooting a wedding and you want the bride in focus all the time, or something like that, it's not useful. Sony AF doesn't know where you want the focus point any more than Pentax AF does, and the only time I've seen it successful was with controlled lighting in rehearsed or staged situations. Once you get into the wild, AF.s and DA 55-300 PLM may do better.
As far as I can tell an A9 is a great camera for things I don't do, and far from up to scratch for most of the things I do. Using my A9, you may get AF.c images I don't, but if I nail the image, the 36 MP of my K-1 will leave it in the dust. The K-1 is better at what the A9 does than the A9 is at what the Pentax does.
It's been suggested that in the right circumstances the A9 will get you twice as many keepers percentage wise. But the K-1 gets keepers, if you take enough images you get what you want. But the A9 never gives you a 36 MP file that will blow up as large as a K-1 on any image.
The only camera I would take instead of a K-1 would be a Nikon D850 for faster FPS and AF and also high res. But it's a lot more money