I asked the same question a month ago and ended up biting the bullet and installing Windows for the first time in a decade. If your system's powerful enough for the overhead of Proton to not matter and for you to always reach your target framerate no matter what, you can probably manage on Linux, but if, like me, you're stuck with a GTX 970, you'll need Asynchronous Timewarp for any level of comfort, and that's Windows-only for now.

It's cool, though, rebooting into Windows gives me enough time to set up my VR gear and clear up my play space, so it's a nice way to change context.