I also use 60Hz screens just fine, saying that getting used to 120Hz ruins slower displays is being dramatic. You can readjust to 60Hz again within 5 minutes. But I can still instantly tell which is higher refresh rate, at least up to 360Hz.
Most people who’ve used both 60 and 120 could tell, definitely if a game is running. Unless you’re asking me to distinguish between like 110 and 120, but that’s like asking someone to distinguish between roughly 30 and 32.
North of 120 it gets trickier to notice no matter what IMO.
I can live with 60 but 85+ is where I’m happy.
On a perfect display you should see just a faint grey circle.
Another test is moving cursor fast across the white page and tracking it with eyes. On a perfect display it should be perfectly crisp, on my display it blurs and moves in steps.
So basically on a perfect display you can track fast moving things, and when not tracking, they are blurred. On a bad display, things blur when tracking them, and you see several instances otherwise. For example, if you scroll a page with a black box up-down, on a bad display you would see several faint boxes overlayed, and on a perfect display one box with blurred edges.
The jump forward doesn't even necessarily feel that huge but the step backward is (annoyingly) noticeable.
Especially wellness.
However, I'm typing this on my Dell monitor which only does 60 Hz. It honestly doesn't bother me at all. Sure, when I scroll long pages I see the difference: the text isn't legible. But, in practice, I never read moving text.
However, one thing on which I can't go back is resolution. A 32" 4k screen is the minimum for me. I was thinking about getting a wider screen, but they usually have less vertical resolution than my current one. A 14" MBP is much more comfortable when looking at text all day then my 14" HP with FHD screen. And it's not just because the colors and contrast are better, it's because the text is sharper.
I’m always baffled people insist otherwise.
Used to have a 27" 2560x1440 monitor at home. Got a 4K 27" at work, and when I got home, the difference was big enough that I (eventually) decided to upgrade the home monitor.
At least to me, with corrected vision, a high quality 1080p video looks better than streaming quality 4k at the same distance.
Glasses make a huge difference when watching TV, and are the dividing line between being able to tell the difference between 4K and 1080p and not being able to discern any.
But a fraction of that distance to my monitor makes even 4K barely good enough. I’d need a much smaller 4K monitor to not notice pixels.
My eyesight isn’t perfect, either.