The LG C4 OLED 55" outperforms the LG QNED80 65" in contrast and motion (9.2 vs 7.8 on RTINGS picture quality) thanks to its self-emissive pixels. The QNED80 offers higher brightness (around 1000 nits vs 800 nits) and a larger screen but trails in black levels. C4 is the stronger pick for cinematic viewing while QNED80 suits brighter environments.