Yeah, this right here, is simply untrue. I've had an LG 720p before that also had below 16ms in PC mode. Jayz2cents is obviously selling you that TV. Still, even a fast TV is still twice or three times slower than a regular IPS monitor, and over ten times slower than a fast TN. Don't let Jay pull wool over your eyes man. Of course its usable, but don't expect it to be a monitor; ie competitive gaming is out of the question. Casual gaming, for sure.
Bottom line, there is internal processing going on and it always has an adverse effect on latency. Monitors have little or none of that, they just feed the signal and all you get is pixel G2G.