I didn't realize that the marketing blurbs quoting "response time" on packaging, were certified by the ISO... (In other words, I thought that it was pretty common knowledge, that those numbers quoted, were basically derived by the mfg in their own proprietary ways, and more-or-less worthless for an objective comparison between mfgs.)
Tom's benchmarking approach is interesting, but I wonder if it wouldn't have been actually better/cheaper (although probably not easier), to re-purpose an optical mouse sensor assembly as a way to measure LCD response times. Remember, most modern optical mouse sensors operate at a claimed 6000 samples/sec. That should be enough to measure response times, I think.
I also wonder about the use of coaxial cables to interface with the device. Surely, the shielding helps prevent noise spikes from intruding on the measurements, but wouldn't that also cause attenuation of the signal? What about the capacitance of the cables affecting the measurements? i dunno, I'm not an EE, but it seems likely.