You may not notice, that doesn't mean nobody does. Also it can depend on your operating system. Windows 10 (maybe everything now?) forces you to be in vsync, so increasing refresh rate has a non trivial improvement on the # of ms for a keypress response.
Now whether you will notice that can depend what environment you are in. If your editor already has an input latency of 100ms then shaving 8 off probably is not noticeable. But going from 20 to 12 might be.
you can just point a phone camera at the keyboard and screen, record a video clip, blow it up into stills with ffmpeg, and then count frames
Even at 60fps, you should be able to see the difference between 30ms and 100ms. Newer phone cameras often have a "slow motion" mode that'll give you 120+ fps video, too
SOME people can see the difference between 30ms and 100ms, but it's almost impossible to actually see it. You'll mostly end up feeling that everything sucks and not knowing how or why.
Now whether you will notice that can depend what environment you are in. If your editor already has an input latency of 100ms then shaving 8 off probably is not noticeable. But going from 20 to 12 might be.