But even if your video card can produce 100 FPS, if your monitor can only do 60FPS then that is all you will get, plus tearing which is annoying. Then add on performance penalties for vsync etc and you have overall a less smooth experience on a 60Hz screen. Yes Hz originated from CRT monitors, but the concept hasent changed. You'll still see smoother gameplay if you have a high end card + higher refresh monitor.
Still, I don't see how a so called "60Hz" screen would be undecent at showing games/movies/whatever. Simply because there's no noticeable effect if you play with 40, 50 or 100 fps. The only situation where this helps is during phases of intensed action where thosee 40 fps rigs fall below 30fps for short periods of time. The human eye can only dissolve 30 fps, everything above is just luxury mostly afaik. Of course, if you remove the frame lock a game will run faster (like double speed, or triple speed or even more, depending on the fps your rig generates), and this might look like it's running faster/smoother. But that's for different reasons..
From my knowledge blurring and stuff that disturbs the screen quality usually occurs when the screen black-white transition times are too high, resulting in parts of the screen having lower quality opposed to situations with low screen activity, which isn't really connected to vsync.
I do think that this "120 Hz" hype is just that - hyping something largely useless to warrant more sales. Just like the first screens with black-white transition times of 11ms or less, which in reality had worse values than 25+ ms screens because of unrealisitc testing settings. Of course they were advertised especially for FPS gamers who liked UT or racing games, although they were garbage.
Afterall, (usually) new hardware will always outperform old hardware, because it's (usually) technologically advanced. For screens it's less energy consumption, better contrast, better transition times, better color saturation etc. And of course if your old screen is like 2 years old you'll notice that the new one will have a better graphic quality, but that's because it's new, not because it has 120hz or whatever salesmen are trying to crap into your head..
However, I'm no expert on this area, so I may be wrong on this.