The problem with response rates is that manufacturers commonly cheat with them. They use different standards of measuring the delays. It's always best to read a review or two of the screen you plan to buy. For gaming input lag is one important test subject. If your screen has a lot of input lag, everything you see on your screen comes back to you on a delay. Imagine moving your mouse on screen to aim - you see where your mouse was a few milliseconds ago, not where it is now in reality or where your enemy is now. This lag often makes the difference between narrowly hitting your enemy or missing him.
For AH input lag is not such a big issue because generally you can't move aim points so fast in it. But for a scissor snapshot it may make a difference already.
