Some very positive impressions from Upload VR here using the 8K at CES 2019 with Beat Saber.
What I noticed with the Pimax 8K is that I was not only able to see the blocks in my periphery still and hit them more accurately without having to actively look at them, but I was also able to perceive more of the environment and its particle effects after hitting a block. For blocks that arrived directly in front of me this meant I could almost feel the block chunks pass by my ears since my peripheral vision was so much more enhanced with the wider FOV.
The first time I tried the Pimax 8K headset was a full year ago at CES 2018 and that demo was TheBlu, a serene underwater experience that was low intensity and required very little movement. Even still back then I noticed some jittering and minor latency issues. Based on my single demo of playing Legend on Beat Saber (Expert difficulty) I can verify that all of that seems to be gone now.
However, one of my main issues from that demo a year ago was still an issue today: edge distortion. At the far edges of your peripheral vision inside the Pimax 8K I noticed a minor effect that caused the lenses to distort a bit. It created a sensation that felt similar to when you get droplets of water inside your swimming goggles — that’s the best way I can describe it.