I think all agree that above 100ms it does become problematic depending on the game.
I also think that most agree that from 20 to 60ms, yes it is noticeable in fast reflex based games BUT it is FAR from unplayable. Some people really need to rethink what that word means!
Thing is, some are flipping out over 40ms of extra lag and for almost any game I have played, the issues of network hiccups, inconsistant frame rate, quality of your mouse/controller all add up to way more error/misses that input lag under 100ms ever could!
I mean at 60 frames per second, 60ms of lag is roughly 3 frames. I don't know about you guys, but my frame rate EASILY fluctuates here and there way more than 3 frames per second!
And if you truly are that high level of a player, you play competitevely (not pro, just for "fun") then maybe it is truly an issue for YOU personally, then damn it this TV IS NOT FOR YOU, move on!
But let's keep in mind that until we have 3 seperate sources that can provide repeatable tests for gaming lag with proper HDR, then all of this is silly speculation!