As crazy as it sounds, resolution and framerate are very important for VR(framerate especially). As it is FOV, too. It can't be "close to 970" level, because it simply isn't. If someone makes a PC headset with the PSVR specs, a 970 won't be needed for it. If you actually read the post you linked to, you will notice the exact caveats I already talked about.
Hhhmm, not sure, the picture is far more complex than you describe.
To start with, as a HMD, PSVR is very good in comparison to both OR and Vive, they are all high end and the differences are fairly minor for the end user experience.
All three companies have cut their suit to fit their cloth, so you can't say "If someone makes a PC headset with the PSVR specs, a 970 won't be needed for it." because of how the PS4 drives that HMD throiugh the external box and because the architecture/software/hardware environment of the PS4 is so different
Because of Sony's engineering approach the PS4 can generate "equivalent quality" images using a quarter of the fill-rate of OR or Vive (notice the speech marks), approx 100 million pixels at 60 FPS
PSVR Specs:
5.7-inch OLED display
1080p resolution, RGB 6220800 subpixels
120Hz refresh rate
low latency under 18ms.
positional tracking with 9 LEDs
360 degree head-tracking
3D audio
100-degree field of view
High-quality optics (not using fresnel lenses)
Extenal processor handling second screen, optical projection and asynchronous time-warp
Hidden Area Mesh rendering reduces render target size by approx 20%