Originally Posted by ski-bum
The Dell monitors are excellent but have slow response time (8ms). Not very good for gaming.
I wouldn't do it.Dell Ultrasharp
Quoted 8ms means next to nothing though. It sure does a lot better than many rated at 5ms, and way better than some panels that are egregiously overdriven like the 2ms 120Hz BenQ XL2410T. Input lag is also very low for the U2312HM.
See comparative pictures and data here for ghosting and lag:
It really depends on the game (which fps?), how much you care about it, and so on. If the action is very fast and jerky, or if you're more sensitive to ghosting than most, I would be hesitant. Otherwise, it's probably okay.
Do note that the U2312HM has lower contrast ratio than many alternatives and also a pretty high minimum brightness setting. If you ever have the lights dimmed (not to mention totally off), over 100 cd/m^2 is much too high IMHO, and this is even brighter than that.