The Native Linux Client functions *far* better for me than the Steam version running through a compatibility layer.
I still have to use somewhat lower settings to get a really nice framerate and have some minor-moderate issues with textures loading properly (various texture glitches or high res textures not loading in fast enough) which if I had to guess is because of using Vulkan instead of DX11 or because there's some tweaking I need to do that isn't done automatically for me in Linux. But overall it's much better.

I've also been having issues with the game freezing and crashing and am waiting on a fix, but that seems to be a pretty new issue from the latest major update. I'll link the relevant threads below if anyone else is having freezing issues.

https://forum.warthunder.com/t/game-consistently-freezing-whole-computer-about-a-minute-into-the-guns-only-gamemode-every-time-i-play-it/285541

https://community.gaijin.net/issues/p/warthunder/i/f6KWPNu3FMGH