Static images the pixel/sde will be evident. If you look at @yanfeng’s non zoomed pics you can see the squares & round details look more stacked & jaggy so to speak. I rhink the 5k would have been a bit better if the per eye was 2560x1600 vs the 2560x1440. More vertical res needed.
@century revisted them here
By your revised desire on sde (haven’t seen O+) neither will be quite there. A dispersion filter though might be nifty on the 8k.