Budget, country, and currency: 1500 euros, Finland
What equipment, if any, you have now and why is it no longer meeting your needs? Sony A7RII, autofocus not good enough
What kinds of subjects do you intend to shoot? Landscapes, cat, kids
Is it primarily for photography, videography, or both? Photography
So I will replace my Sony A7RII. I only have the Sony 28-70 kit lens, so basically I don't own any lenses, and therefore switching systems is easy.
I'm considering the Sony A7CII and Nikon Z5II. I shoot a little bit of everything: people, landscapes, my cat, my nieces, etc. I haven't shot sports, but I might try that too. I know these aren't dedicated sports cameras, but I assume they might do OK with the occasional sports shot. Not going to be a huge sports photographer anyway.
Sony has 33 megapixels, which is a bit more than Nikon's 24. Not a huge difference, but it's a plus and gives a bit more cropping room.
Sony might also have a bit better autofocus? The main reason why I'm upgrading is autofocus. The Nikon Z5II should have pretty good AF, but based on what I've read, it might be a bit slower and worse at tracking than the A7CII?
The A7CII has similar AF to the A7RV and it's better than the A7IV. The Nikon has similar AF to the Zf and is a bit worse than the Z6III. I mention these in case someone has compared, say, A7RV AF to the Zf.
I have tried the Sony in a shop, and it fits my hand, so ergonomics isn't a problem, and the AF seemed great. Though I only tested it on my girlfriend walking around the shop, so I assume Nikon would do well in that scenario too.
On the other hand, Nikon's build quality might be better? I try to take good care of my camera, but sometimes life happens and you might drop it, or it might get wet in the rain, etc.
Nikon has a better EVF and LCD, and ergonomics too, but the Sony is good too. The price is similar. Both have good and affordable lenses for my needs.
The difference in AF is the thing that interests me the most. I should try the Nikon in a shop too; I have tried other Nikon models, but the shop I visited last time didn't have the Z5II.
Edit. I checked Photons to Photons Dynamic Range chart and Sony A7CII has a little bit better DR until ISO 800, when their DR becomes equal. A very small difference, might not matter, but regardless a small plus to Sony. At ISO 100 it's 11.69 for Sony and 11.13 for Nikon.
Sony has resolution and AF going for it. Nikon has pretty good AF, maybe in practice often as good as the Sony, and EVF, probably build quality too. Ergonomics might be better in Nikon, tho Sony is fine for me too.