That 60Hz works out to 16.7mS. So the usual is to have a LCD go from full on to 50% off in about that time as a bare minimum. Your set looks to be 120Hz so that's where the 8mS is usually from. Since we can't send more than 60 frames a second, 8mS is just fine for a 120Hz display.

What many gamers gripe about is input lag. http://www.displaylag.com/lg-samsung-sony-input-lag-results-4k/ lists some models but Samsung seems to always fair OK to great.
Bob