RTINGS YouTube-vid shows much reduced viewing angles in LG G5 (probably due to the tandem panel: the more panels are stacked and the longer the light tubes become, the worse the viewing angles become), let's see if it's addressed in G6. So far Quantum Dots seem superior (no need for stacking panels).
LG's mid-range OLED range is finally getting an advanced tandem OLED panel in the form of the LG OLED C6, which is said to be very bright. The LG OLED Evo G6, on the other hand, is getting a brand-new RGB Tandem 2.0 panel complete with "Brightness Booster Ultra".