[Kozlok]

One of my photography challenges is photos of the grandkids. I'm using a K-70 now, and I seem to miss a lot of shots because of trying to get their faces in focus. Lots of potentially great shots spoiled by (slightly) missed focus. My best bet is to use single point focus, in AF-S, and try to get the focus point right on their face. My guess is that a K-3 III set in AF-C and zone focus will have a much higher keeper rate, but before I pull the trigger on this big of an expense, I'd like confirmation from K-3 III users that the autofocus performance on faces is significantly improved.

[reduno]

I think we need to know a little more about the setup you are using on the K-70 in order to determine if the K-3 III will generate a higher keeper rate. You indicated you are using single spot focus on the K-70 and trying to center this on the grandkids faces. I would be curious as to what lens (or lenses) you are using and what the other camera settings are (ISO, shutter speed, aperture). I know kids can move pretty rapidly but the K-70 should be capable of focusing accurately if the spot is on the target. With kids, I tend to pre-focus by half pressing the shutter button, and then fire the shot when recomposed and the action happens.

[caliscouser]

Will be somewhat lens dependent, but I would agree that anything up to KP level AF can't keep up with kids for the most part.
K-3iii looks like the first Pentax camera that could potentially keep up, or at least have a good keeper rate. That's also part of the appeal for me as well.
Curious to see what others have to say.

[Kozlok]

I went ahead and did an order through Adorama; worst case is it doesn't meet my needs and I send it back.

[clackers]

One of my photography challenges is photos of the grandkids. I'm using a K-70 now, and I seem to miss a lot of shots because of trying to get their faces in focus. Lots of potentially great shots spoiled by (slightly) missed focus. My best bet is to use single point focus, in AF-S, and try to get the focus point right on their face. My guess is that a K-3 III set in AF-C and zone focus will have a much higher keeper rate, but before I pull the trigger on this big of an expense, I'd like confirmation from K-3 III users that the autofocus performance on faces is significantly improved.

Well, the big difference is that your K-70 does face focus (it's really eye focus) in Live View, the K3-III does it in the OVF as well. Of course your settings have to be correct.

[Ishpuini]

Not just the AF IMHO. The fact that high ISO is much better than previous cameras, would mean that you could go a bit higher in the ISO and stop down the aperture a tad more to get more depth of field as well.

And higher burst speed could help with kids too...

Not a bad choice if you can master the tool.

[Rondec]

I think pared with you DC lenses (like the 16-85) it should do really well. Some of the older SDM lenses and screw driven lenses may not do quite as well.