I have an LG OLED CX and it's amazing! Also have a C9 I'm trying to sell if anyone is in the PDX area... It's so hard to describe how much better HDR 4K is but it's so much better. I think my plan over Xmas and NYE is to watch the UHD LOTR Extended cuts.
Coming from a 10 year old 42" LCD, the upgrade to a 65" 4K was insane. I definitely watched some YouTube videos to tweak the settings, but I find myself going back and forth from Cinema to Standard depending on the show.