I don't think you should be downvoted for answering parent's question. It's helpful for understanding a mindset that not everyone possesses.

Which version of Windows do you currently run, and what do you feel Windows has or does that makes it superior for your development work?

Not GP but Windows-primary as well. Linux desktop has improved a lot over the years, I quite like KDE Neon, but lack of any viable RDP alternative is a deal-breaker for me (I've tried all the alternatives, they're not there). I've never been a consoles-only guy, even though I grew up with DOS. I also rely on RDP to separate work and home machines.

Windows also stable and performs well, ie no silly kludges needed like oom-killer.

I usually stay a bit behind the curve, roughly keeping with the old "don't upgrade until service pack 2 is released" adage. Just installed Windows 11 on my work machine, running Windows 10 at home.

I run Windows 11. It has first-class support for Linux, with WSL, and the Windows Environment has first-class support for NVIDA graphics, popular productivity and entertainment software. It's reliable, stable, and performs well, with commercial support and scheduled major and minor updates. It's consistant. I can develop software for Windows 11 and be sure that everyone else with Windows 11 can run it.

Windows 11 has ads in its file manager, right?

I've heard this as well, but I run windows 11 for work, and can confirm the file manager has no ads in it (I don't know if there are alternative versions of Windows 11 that do, but it definitely isn't true as a blanket statement)

Most of the complaints I hear are from people running an unlicensed copy and complaining it nags them.

Legally, FreeBSD is just an imitation of Unix.

Linux is just as much of a Unix as any OS in actual widespread use.

There are other real UNIX to chose from.