If I ever get fu money I'm going to start double-blind testing everything - screen refresh rates; mouse rates; coffee preparation methods; speaker cables[1]; bitrates for media; compression for media; everything I can.

Can't say for gaming, but 120Hz is great for watching movies/anything at 24fps. With a 60Hz screen you gotta do something to make that 4:5 ratio work (either holding frames, or attempting to interpolate/interlace). At 120Hz, you got a nice clean integer ratio, so you can watch 24fps 'as it is'.

Anecdotally... The way I perceive framerate is related to the resolution. Take a horizontal panning shot at 720p/60hz... a vertical line might move 2 or 3 pixels per frame. At 2560*1600/60hz the same line jumps 4 or 6 pixels per frame and starts to appear discontinuous in vision. High contrast makes it more obvious. Motion blur removes this in exchange for input lag, but high frame rate is a better solution.

I've had numerous discussions with people about 60Hz vs 120Hz, including one where a friend cited some study (sorry no link) which claimed that, perceptually, people couldn't tell the difference between these two refresh rates. I was incredulous. I'd been playing Quake at a high level for a number of years and anything lower than a v-sync'd 120Hz setup was painful, on the flip-side, playing 120fps@120Hz (CRT) felt so fluid, like water (hard to describe, you have to play on the two setups to feel it).

I haven't had the same experience on any flat panel display I've used till now but I'm on the lookout for a good 120Hz LCD gaming monitor in the hope I get the same experience again.

I recently took a resolution downgrade to get a vg248qe for the 120hz with lightboost. See here: http://www.blurbusters.com/zero-motion-blur/lightboost/

If you ever have a chance to play with a monitor at 120hz, especially with lightboost, it's so obvious that you wouldn't feel the need to have a double-blind test. If you're not playing games, it's most noticeable when scrolling down a page in your browser or moving the mouse.

It's very easy to spot the difference for anyone, even the uninitiated.

Just launch your favorite first person shooter, and rotate the view very quickly. Of course the game needs to be running at framerates above 60 FPS, and with v-sync off. (Or at framerates above 120FPS, with vsync.) The difference between 120 Hz and 60 Hz will be immediately visible through the "smoothness" of the rotation.