I used to play in sponsored Q3A clan tournaments and even when I was at my best (I am too old and slow now) I chose 85Hz at 1024x768 over 120Hz at 640x480 because the refresh rate wasn't the bottleneck, it was always about getting your mouse and mat combo right.
I feel like 85Hz would be a distinct disadvantage on an LCD these days. 85Hz sounds low, but the pixel response time was a true 0ms, with zero sample-and-hold blur. Many of us old-school competitive gamers will probably still say that LCD displays never really caught up; I think they finally have, but it took LCDs around 25 years to do so and it's not like-for-like either because CRTs still outperform every other technology for sample-and-hold blur, which affects motion clarity more than anything else.
I'm not giving up my strobing 120Hz Odyssey. There are far too many other advantages to modern displays, but sample-and-hold blur is the key LCD disadvantage all of these high-refresh gaming displays are trying to fight and in that respect the CRT is still unbeaten. We're just finally getting to the point where it's good enough, either at 240fps at 240Hz, or at lower framerates with strobing/BFI.
500Hz would be an upgrade over 240Hz, but only if the technology behind it can actually generate images in 1/500th of a second. IPS cannot, for sure - and very few combinations of GPU/CPU/game engine can, either.