for anyone buying this laptop and is sensitive to PWM, BEWARE there are 2 suppliers for the 144Hz screen. There is the one in this review, made by LG and another made by BOE (BOE HF NV156FHM-N4G) The BOE model has TERRIBLE PWM. While I can't measure it properly, i used my camera, and took pics while changing the shutter speed between pics until the evidence of flicker was not noticeable. Doing so, i was able to find that at 1/200 s shutter speed, aka 200Hz, the camera and backlight were almost completely in sync, with which a conclusion can be drawn that the BOE panel used on the Blade 15 has a PWM of 200Hz. Further more, the flickering was noticeable at all brightness levels lower than 100%.
tl;dr
the 144Hz BOE panel has a PWM frequency of approximately 200Hz at any brightness level below 100%. Getting a Blade 15 with the LG display is a gamble.