Got my 1st 4K TV last year, after 10 years of owning a 1080 p Samsung OLED TV
That Samsung actually had great picture quality but being OLED it eventually got burn in
Since I don't watch tons of TV got a cheap TCL 4 Series, 4K TV (Roku)
For the price it's really great, but since it's a cheap non oled TV the HDR looks terrible on it, dim and poor contrast.
However, since I ready had qn Apple TV 4K, I use that instead for streaming and the Apple TV allows to switch to SDR (no such setting in TCL/Roku's menu) and it looks much better in SDR
Also sometimes black backgrounds can get those dark gre1y/black squares , especially on YouTube
But overall, no complaint