You called it.some people are more sensitive to such differences than others. i remember vividly how i connected my first 120 display, moved the mouse - on the windows desktop and the difference was so obvious to me that i said "wow" aloud, although i was alone. pair that with ulmb, as i found motion blur nauseating in shooters, and you have another world. at least, that was my experience.
a friend still plays on 60 hz, because he prefers the more vivid colors of ips and 4k, and the funny thing is, he still beats me usually, simply because he has far more time for gaming than i do and experience still matters more than frames. (as does talent, well, he has much better dexterity). and he has more fun with a beautiful image, so he plays more often.
meanwhile, my next upgrade will be a 240 hz monitor, i have already tried one and it felt much smoother than my current 120 hz screen. to me, smoothness matters more than looks. perhaps i'll play more if it's more fun, and get better
I'm one of those ips 60 guys haha