Re: I call bullshit
Although you can see an easy measurement of ping, you can't see the other "hidden" lag.
The ping is just the time for a single packet (maybe not even a game packet but an explicit ping packet) to reach the server you're playing on (and return, I assume).
You almost certainly lose 1/60th of a frame no matter what anyway, because of screen buffering and game programming techniques. That's 16.7ms. Then your mouse is probably optical and USB - that could easily add on the same number of milliseconds between you moving it, it being sense, processed and got to the main CPU for it to act on it (but only when it next hits an event loop which could be half the above quite easily - so another 8ms or so!).
Then the time to send the image down the HDMI cable and the HUMUNGOUS time the LCD might take to process it (even a 5ms full-dark-to-full-bright time means nothing as a lot of modern LCD's "buffer" the screen updates even further inside themselves so although technically true, you could be 2-3 frames behind what you're think you're supposed to see - yet another 35+ms!).
There's more to responsiveness than ping time. A lot more. But ping time is easily measurable without any human bias at all. The rest aren't. There's no way to reliably measure just how long it takes you to respond to a screen change without taking a reaction test. And there the greatest error contributor is your brain processing and nerve response, which swamps all these other factors anyway.
I have run game servers (CS 1.6 etc.) for years. I consider 100+ ping unacceptable personally, and 200+ unacceptable on anyone entering the server. But my reaction times in even the quickest test of pressing a mouse button when you see a dot swamp anything that my PC could be waiting for from the network. What they are saying with the "150ms" measurement is that there's an awful lot of other stuff other than ping that affects perceived responsiveness in the average gamer's setup. But it still doesn't mean that they have solved those problems themselves or that their system isn't liable to that same 150+ms "technical" latency.