I typically run my NEC 950+'s w/R9700 at 1024x768 @ 85hz. Lower bothers me but higher I dont see too much difference so no need to work the monitor harder or get myself used to too high of a refresh. The only time I will go higher refresh is for stereoscopic 3D glasses (edimension). Since you lose 1/2 your refresh with those, you need to boost up your refresh as high as efficiently possible, for me thats 120hz@800x600.
Refresh rate sensitivity will vary with each person and each action and each condition in which they view their screens. So really its about what you are comfortable with and what you have experienced. Blurriness of the image is also a big factor. If you have an older monitor and video card that is not as crisp as some new .22 dot monitor at 1600x1200, a lower refresh rate won't seem that much different then a high refresh on a clear monitor. In fact the redraw on a high refresh, sharp monitor may be more apparent then the older blurrier setup. TV's work like this to a degree. They are blurred a bit so you dont really notice the 24fps, but if you played Unreal Tournament at 1600x1200 resolution at 24fps, you'd notice the frames for sure.
Refresh rate sensitivity will vary with each person and each action and each condition in which they view their screens. So really its about what you are comfortable with and what you have experienced. Blurriness of the image is also a big factor. If you have an older monitor and video card that is not as crisp as some new .22 dot monitor at 1600x1200, a lower refresh rate won't seem that much different then a high refresh on a clear monitor. In fact the redraw on a high refresh, sharp monitor may be more apparent then the older blurrier setup. TV's work like this to a degree. They are blurred a bit so you dont really notice the 24fps, but if you played Unreal Tournament at 1600x1200 resolution at 24fps, you'd notice the frames for sure.