> 120Hz is incredible for gaming.
...if you're playing with v-sync :-P. I got a (rather expensive too) 165Hz monitor recently and the main benefit is to lessen the lag that Windows' forced composition (which also does v-sync) has. But in games i always played with v-sync turned off (i do not mind the tearing, unless it only happens at a fixed position i never really notice it) and the responsiveness was already very high. And on Linux and older versions of Windows where i could disable the compositor, i already had high responsiveness on the GUI too (if anything i feel like even with the 165Hz monitor, the Windows 10 desktop is still not as responsive as Windows 7 and previous versions of Windows were with the compositor disabled).
Though a large issue with that is how modern monitors work. I also have a CRT connected to an older computer here which can do 120Hz and the motion feel is considerably better to the point where i wonder what the hell was wrong with people in the mid-2000s to switch away from CRTs when in pretty much every other area except size and weight, the CRTs were superior - especially at the time (better image quality, better and true dark colors, better responsiveness/no 'response time', higher refresh rates, higher resolutions, variable resolutions with no scaling artifacts, etc). In fact a reason i decided to try a 165Hz monitor was because i recently connected that CRT to a machine that can do 120Hz and have some games to run at 120fps and wanted that experience for my main PC too.
(sadly i do have a feeling that if i hadn't used a CRT the last few years i'd be more enthusiastic about my new monitor since i do not think the currently technology can do much better - at least without going to something like that gigantic $3k OLED monitor though even that would annoy me for its size)