Index is pretty crisp even at 100% SS in Steam. I’d say the Index is also brighter with better colors too, although I haven’t messed with the newest beta yet. The Index really “pops” with light/color, and the lower persistence of the Index makes things feel a bit more lively too. A lot of immersion is taken away, however, when the awful glare shows up in my peripheral vision.
Pimax 5K+ at 100% SS is also really crisp, maybe more than Index (may do some comparison tests), but I can barely play any games at 100% on the Pimax due to performance. So in terms of performance, I think Index wins too, even at 120Hz (my SteamVR recommends 108% SS for 120Hz). 120Hz is nice and smooth and immersion-enhancing, but it’s not a huge game changer, especially with the glare constantly reminding me I’m looking through lenses and screens. I’m not sure of the actual resolution values, but I see 100% SS as the point where it’s close to “native” resolution. There are those “black dots” on both headsets, however, I’ve heard the newer 5K+ is improved. Mine are pretty bad on the 5K+.
There’s something interesting going on with the Index in terms of SDE/pixels. When I move my head, I can sometimes notice the pixel pattern, however, when I stop and focus, I don’t see pixels. I wonder if the dual-lenses do something to mitigate SDE at the focal point.