I hadn’t had the time yet to do much 90/120 hz testing, I just have been running at 120 hz and the image looked really nice. But after your words I just tried it and I figured, let’s try it with a video in SimpleVR player. And I immediately felt I could see the difference, especially when the camera pans/turns, I see some ‘micro stutter’ at 90 hz that I didnt see on 120 hz, the image just feels extremely smooth when the camera pans at 120 hz.
However I do know that your mind can play tricks on you (like many audiophiles claim to be able to tell the difference between 320 kbps and FLAC but then fail in blind tests). So I did some blind tests, actually very easy, you just put your mouse in the middle between the 90/120 hz buttons and then move left/right, slightly up down, without looking and then try to end where you think is the middle between these 2 buttons and then without looking at the settings screen restart SteamVR. And yes, every single time I did this I had it right, so it wasn’t my mind playing tricks on me, but 120 hz definitely is an improvement. And the interesting notion here is that those vids are of course 60 hz, which implies that the other frames are all calculated but this really works well…
Of course that doesn’t mean everybody sees it, like you said. But for me it’s now so obvious that I don’t want to go back to 90 hz.
BTW, another test is just in the SteamVR room wave your hands, I think @jojon used this too as a quick test; you always see some ‘ghosting’ when you quickly move your hands, I mean your mind sees (‘remembers’) where the previous frame was and this distance between the previous frame and the new frame is much lower on 120 hz, it’s much closer to reality.
Haven’t done 120/144 hz testing yet, will do that later today but I’m assuming I won’t be able to see much difference between these 2, since 120 hz just looks extremely smooth to me already.