I own a Valve index and have eben running it exclusively on a linux gaming PC for the last couple months. There are problems. The VR games themselves are generally good. Games generally "just work" but some of the other VR bits and pieces are troublesome. Each time I play I have to bounce around menus to enable sound through the headset. And very few media players work in linux (codex issues). Skybox VR works, but not on the latest version of proton. I still haven't figured out how to watch youtube in VR.

I would still recommend VR gaming under linux for all the same reasons I would recommend linux over windows generally, but not to a casual gamer expecting a seamless experience.

It works, but still beta quality. Steam still crashes every time I start SteamVR (restarting Steam afterwards works though). There is no official way to play VR videos. Half-Life: Alyx has enough bugs that Valve still does not advertise that it supports Linux on the store page. SteamVR and Half-Life: Alyx have both not been getting many updates on Linux. Maybe I'm wrong and there are fixes coming up but honestly it feels kind of like whoever at Valve got VR running on Linux lost interest.

It works somewhat, but the more advanced VR features like async reprojection or motion smoothing don't work, and there's a definite performance hit. The FPS drop for general gaming is less noticeable, but it's really important for VR.

Through proton, it's fantastic. The native Linux stuff is hit or miss unfortunately.