Keep in mind that response time is completely meaningless because there's no industry standard. Even if we were to believe Acer's 4ms GtG, we also have to keep in mind:
1. This is still under the cycle time of 144Hz (6.94ms)
2. Colors rarely go from one end of the spectrum to the other. And even then, it's only the sub channels that may do it and humans are less sensitive to color than pure luma.
To put in perspective why response time is kind of meaningless, check out this post: http://www.overclock.net/t/1221711/what-does-response-time-2-ms-gray-to-gray-mean-in-specs#post_16578402 (note that a 14ms monitor somehow looks better than a 5ms monitor)
Also to those who claim 144Hz is automagically superior, just because you receive more information doesn't mean it's meaningful to you. The few tests I've found where there were as blind as possible testing between 60Hz and 144Hz, there's no conclusive evidence to suggest that 144Hz is objectively superior. I mean, we can blame media for making us used to 24FPS (but you also have to understand that those are preprocessed to hell and back to smooth out the motion whereas games have no such thing).
I mean, the average conscious reaction time for a visual cue by humans is allegedly 0.25 seconds. You could do better, if you were trained so that muscle memory takes over. And really, you can probably get that at 144Hz or 60Hz. I used to play StepMania and DDR at a paltry 30FPS and kick butt. Sure I prefer the 60 FPS versions now, but once muscle memory takes over, frame rate to a certain point is moot.