Actually, CP, even an increase from 60 hertz to 85 produces enough change to be noticeable by the human eye. I've seen how unrealistically smooth graphics are at 85 hertz, so I can only imagine how it must look at 120.
I use either 85hz or 120hz depending on the resolution, and it's a big improvement over 60hz in old games that can maintain such a framerate. The difference is especially obvious in flying games with smooth and steady turning motions, such as FS2 or the Descent games.
I call bull****.
Yes, a human can definitely notice a change in flicker rate, however as far as perceived motion goes, there is really little effect beyond 60 FPS. There is a reason why movies are still shot at 24 FPS.
Movies use blurring and interlacing techniques and don't look quite as bad as a game does at 24fps, but they still aren't entirely smooth. Compare a movie to walking around in real life. You should notice a difference if you look for it.
Read
this article. There is no threshold of X fps beyond which things are imperceptible. Humans don't see in terms of frames. It depends on the types of images involved as well as what the person is used to. As you said yourself, flickering on a CRT is noticeable well beyond that.
