Reply to D850 or Z7 II? Which to buy

Sorry to hear that, I would hate to lose my D3s like that. I don’t use it much these days, but I still keep it (together with a D3) and shall never part with it, I think.

Anyway, the answer to your question is easy and twofold:

First, it depends on lenses. Z mount lenses are unequivocally better than F mount ones, often by a large margin. Whether you are willing to rebuild your collection of lenses or not, that’s the first question. Otherwise, it will mean using lenses not as good as those you could have, with the added downside of the FTZ adapter (one or several) that works perfectly but is bulky and adds weight.

Second, it depends on what you mostly shoot. If you do a lot of fast action photography, you’ll probably be better off with a D850 for tracking autofocus. The Z models are catching up fast, but aren’t there yet (and there is the issue of the viewfinder blackout, short but there). They soon will be, though. On the other hand, they are the future, and personally, I never regretted going mirrorless (although I also did keep my D850).

Finally, there are a couple of “secondary” issues, such as can you habituate yourself to an EVF? Are you seeking smaller and lighter form factors?

I shoot landscapes, old stones, studio photography, macro, architecture. The Z7 is perfect for me and I almost haven’t used my D850 for more than two years now. Haven’t seen the point in updating to the Z7 II model for my use cases, but certainly waiting for the high-end model that’s rumored to be announced later this year.