It works amazingly well and I can't imagine going back to Windows for a PC that is built only for video games. I use it on my "Gaming HTPC" (Ryzen 3600, Radeon RX6600, Fractal Design Node 202) and it brings a great console experience to my TV, with access to my PC game library, without being locked into a console ecoystem, and without the enormous cruft and user hostility that Windows has you manage these days.
I'm a pretty casual and patient gamer, and for that use case this Steam machine experience is unmatched - despite being built on desktop Linux, it works out of the box and requires zero manual maintenance. For dedicated gaming boxes this Linux user experience is significantly better and easier to use than Windows - we're truly living in the future.
[1]: https://bazzite.gg
[2]: It's built on top of Fedora and Universal Blue, so under the hood it's different from SteamOS which is built on a custom immutable version of Arch Linux. However, that implementation detail is actually almost totally irrelevant if you want to play games since all software is managed by Steam and Flatpak on both systems.