Belial I tried doing some research. Shoryuken said there's no lag but they didn't show any proof of how they tested it.
There was a thread about TVs
http://www.8wayrun.com/threads/hdtvs-vs-crts-for-tournaments.6427/.
Your best bet for absolutely no lag is to buy a Digitial Signage monitor with analogue input; digital input such as HDMI produces lag. Otherwise if CRTs still exists I might as well buy one for a much cheaper price.
On a side note, the true way to measure latency is to connect the Hori LCD H3 and a CRT (given that there's no lag) to a computer through analogue input. Make sure both monitors are visually simultaneously running at the same time then run a timer then take a camera and take a couple of snap shots.