well to be honest, you will need to have at least a gtx670 sli setup in order to take full advantage of a 120hz monitor. And I am not talking about 3d here, imo the biggest advantage of a 120hz monitor is that it allows your eyes to perceive 120fps instead of 60fps. So when you run games with 100-120+ fps, your eyes feel this sense of smoothness thats really hard to describe, its like a surreal experience. However, in order to get that experience, you need to have enough horse power. Your single gtx 670 will own any game with -60fps but to reach that 100-120fps level in games like battlefield3/crysis2, you will need dual 670s. Same goes for 3d vision, you will have to turn off some eye candies if you want to run certain games in 3d on a single gtx670 rig. So I say, if your planning to add a second gtx670 to your system, then by all means save up for a 120hz monitor. Otherwise, get a quality 60hz monitor. The Asus one would be really good- but at least try to get a 23'' monitor, 21.5'' is tad too small.