PSVR uses 60Hz reprojected to 120Hz, so gets a 33% performance advantage over Vive and Rift which run at 90Hz.

It uses RGB-stripe instead of pentile, and actual has more subpixels than Vive or Rift, and it picks up some big performance advantages there (on Vive and Rift you more or less throw away 33% of the subpixels you spent time rendering). It won't quite be up to their quality because your eyes are more sensitive to green, but at current low HMD resolutions green sensitivity less significant than on phones.

With both factors combined, 33% lower framerate requirements 25% or so lower nominal res with much of the quality retained, it will have something like a 50% performance advantage over Vive and Rift. Putting it close to parity with Rift's GTX 970 recommended-spec.