After using the LG C3 for few months I must say that I am a bit disappointed with the picture quality.
For reference I have another TV, Sony x900f which i bought a year after it came out.
I have followed a guide to setup everything for sd and hdr movies and also sd and hdr gaming, I followed this guide:
and although the movies and games look great somehow the image looks dim.
I have tried many movies in hdr and i was always disappointed with the image. I would play the same movie on my Sony TV and it would look better. Also playing hdr games (on series x and PC) have the same problem, it looks very dim, yes some of the highlights like glowing light bulb and some smaller things are bright but the whole image doesn't really gets bright enough.
Overall when watching movies or playing games i still prefer sony, and i regret buying lg even though lg has more features (vrr, gsync, 120hz).
I learned the hard way, I will never buy another oled ever again.