So far personally I've only had one really bad performance problem. I went into a cut scene and my FPS tanked. I quit the game started it over and Everything was fine.

That being said I'll talk a bit about my set up and specs. I'm running Linux, I use Pop!_OS and I'm running TK-Glitch 5.8 custom kernel for gaming.
I'm running the game in Steam with GloriousEggRoll latest proton. I'm running the game in Vulkan so I don't have do lose performance doing DX to Vulkan translation.

If none of that makes sense sorry, It's not as confusing as it sounds and all I had to do to play the game was install it and pick the GE proton setting in Steam.

My specs are
Ryzen 5 2700x using XFR to overclock
EVGA 1660 Super
16 gigs of Ballistix sport 3200mx with custom timings
Game is running on an inland NVME ssd.

I'm running in Ultra settings. I don't ever experience a 2-3 second freeze in Vulkan like others have experienced. I do have some microstutter when turning the camera.
To be honest I'm pleasantly surprised how well the game is running before optimizations have been made. Here is a screen shot of what FPS I'm getting here and what resources are being used.
I think the lowest I've ever dropped was low 50's besides that one time in the cut scene they tanked.
[img]https://ibb.co/hgjYP3L[/img]