In nixOS my USPs are its reproducability and its “integrated toolchain manager”.

1. Backing up and restoring /etc/nixos is enough to re-install all system relevant software, while backing up and restoring ~/.config/nixpkgs is enough to install user related programs and their configuration.
2. In each project I can have a shell.nix or a default.nix which describes the development environment. Usually one loads this environment manually, though tools around that have been developed which make me able to enter the environment on dir change. as well as aggressive caching of those environments.

Would you recommend nixOS for development? I will have to make a decision in the next 2-4 weeks about a Linux development environment and I kind of forgot about nixOS.

For macOS my USPs are definitely the [alleged] high security of the system. Apple has gone out of their way – and often broke a lot of programs and scripts which isn’t nice of them – to make sure some plain virus, ransomware or rootkit won’t have an easy time taking over your machine. I do however have to say that the performance of programs under macOS has been mediocre. Linux reigns absolutely supreme here and stomps macOS like there’s no contest. Still, I like macOS’ beauty and opinionated approach in general and I feel that it’s suitable for a lot of people. But I do start to question if it’s a good fit for professionals at all…

For Linux my USPs are, obviously, extreme customisability (although that’s not always a good thing; I am more in the camp of people that want a good minimal working system out of the box and not an installer with 50 steps and checkboxes) and the raw speed. But Linux seems to have long way to go in terms of isolation (to this day, any X11 program can read and record keystrokes, and Wayland is sadly not that useable for everyday usage, I hear).

For Windows 10: ubiquity. A lot of Linux fans love to trash it but its backwards compatibility and stability (ever since Win7 which is a lot of years already) should give them pause and hopefully make them strive for a better ecosystem. I know it’s not Linux’s fault for many OEMs who never make drivers for it – or that games must use emulation / pass-through layers – but if Linux wants wider adoption it will have to climb 3 mountains, not 1.

Especially with WSL2, Win10 is now a very solid contender for a workstation + gaming OS and I imagine a lot of people might forgo their macOS laptops for work and just move to their Win10 PC for that.

I wouldn’t consider it if I had to learn it from scratch. Though using a random Linux or Mac with nix as auxiliary package manager for the shells, with regular installed toolchains as escape hatches is what I’ve done first to learn how to deal with nix peculiarities.