I am testing this out with Skyrim, and so far it's great! I had to enable beta updates for Steam, then go into settings and enable Steam Play for all titles. I now have Skyrim + SKSE installed through my Linux Steam client! One issue so far seems to be an inability to install workshop mods, so those I'm having to do manually. It uses a custom Wine implementation, and DirectX 11 and 12 are implemented through Vulkan. I have not played the game a lot yet, as I have been working on getting my mods set up, but I have to say that performance was what I would have expected when I did run through the intro - very fast and smooth on a Ryzen 5 + Radeon RX 580. The experience is absolutely seamless. I hope that this will be the beginning of the end of the domination that Microshaft Windows has so long had over PC gaming. Gaming was always a major hurdle for people considering a transition from Windows to Linux or Mac. Most of my Steam library is multiplatform because I was never willing to put up with Windows just for that. But now my options are much improved!
I know little on this subject, other than what I have read. To me it seems "Steam has lost it's steam". At first it looked like the Steam Machine/Game streaming was it. Slick console backed by a company with a great name for quality...and then...nothing. The early chatter turned into occasional "what happened to Steam Machines?" ... to "Steam is dead"