Question: is 2ms better than 4ms?
Answer: is there a big difference between a 2ms respond time and a 4ms? ... For most people, images would be ghosting-free on an LCD with a 16ms response time or better. That being said, gtg response times = (1/2) actual response time. So a 4ms GTG is more like a (real) 8ms response time throughout the spectrum.