i went from 60 hz to a 120 hz screen. i can't really put into words how it was better, but overall, my mind was telling me something was different and it was a good thing.
i upgraded to a 165 hz screen when i bought a matched set for triple monitors. i could not tell at all that i added a bunch of extra fps. sure i could put a counter on the screen that told me it was higher, but i was not experiencing anything different than when i was at ~120 hz.
throw in a bunch of various articles i have read on the topic and it seems like getting to 100-120 hz is a good thing and worth pursuing. trying to get to 1000 fps, is just a case of wasting money.
as cheap as you can get a quality screen around 150 hz or so, it's worth it if you are buying anyway. but spending crazy money to get steam to tell you it is putting out 500 fps to an expensive 360 hz monitor, is more psychological than anything.