"And this panel didn't work any miracles. What we're dealing with here is a typical characteristic of PVA matrices. As transitions between values become slighter, the electrical field applied to each pixel to change the plane of the crystals' orientation becomes weaker. For a slight change, paradoxically, the rotation the crystal has to make is also slight. But with the PVA technology, latency skyrockets when the difference between the desired color and black is slight. And that's what we see here: Latency reaches a high of 120ms, whereas the panel's specs are 25ms according to the ISO standard. "
That's directly quoted from THG about a recent test on some cheap lcd panels. I'd only personally use an lcd panel for gaming if it's response time was in single digit territory.