I think the Rift S RGB sub-pixel is designed in a grid, while the existing Rift Pentile sub-pixel used a 2 - 3 -2 sort of brick layout. The Vive OG used a diamond with fairly big gaps, showing that it hasn’t aged well. The spaces between the sub-pixels are all different too.
I think the basic resolution of 1280x1440 per eye on the Rift S really only tells part of the story. The clarity they have got out of that RGB sub-pixel layout, plus the range on that LCD panel make it a really nice display.
The Reverb stuff is down from here - Tested did a good review: VR News: HP Reverb - Second Gen headsets are on the way - #170 by fearlessfrog