The difference is huge. I can see it noticeably. Once you try 120 Hz monitor it is really hard to go back to 60 Hz.
Movement with 120 fps is much smoother and much more comfortable than 60 fps. I feel mouse lag sometimes with 60 fps that I don't notice with 120.
However me personally I don't see a difference between 65 fps+ vs 120 fps.
So this really nulls the theory that human eyes can't see above 60 fps.
Movement with 120 fps is much smoother and much more comfortable than 60 fps. I feel mouse lag sometimes with 60 fps that I don't notice with 120.
However me personally I don't see a difference between 65 fps+ vs 120 fps.
So this really nulls the theory that human eyes can't see above 60 fps.









EDIT: Ooooh, now I see what you're saying and fully agree with you! 
