I’ve got a 2 y.o 75” Panasonic LED UHD TV and watched the recent 9s in 4k and some of the WC 9s from last year. Small details like the players’ faces are sharper. It’s basically like watching in person.
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@Generalzod said 55” and smaller you probably won’t see much difference, but 65” & above, there’s certainly improvement. As to how much, it depends on the source. Also, 4 times the resolution of HD is not even the best part of a UHD TV. The HDR and wide colour gamut probably add more, creating a rich, more realistic image. Again depends on the source as I’m not sure I’ve seen HDR on anything other than UHD discs. Perhaps a show on Amazon Prime. Even on blurays (the best way to see the brilliance of 4k) there is quite a bit of variation in image quality depending on the way the film was shot etc.
I’ve had buyer’s remorse in the past (mainly because uhd blurays are exxy) but glad I got the TV now. I’ve watched/recorded lots of uhd foxtel movies, which even if paying for it (it’s been free for almost 12 months) is much better value than buying discs.
Even playing PS4 pro, it makes a big difference (mainly the HDR on games that have it) e.g; MLB: The Show 19 looks less harsh and more natural with HDR on. PS5 and upcoming xbox will be even better.
I’d say get one for sure if you can. The list of movies and content available is growing rapidly now and the TVs are improving heaps too.
Netflix, Prime and Apple TV have plenty of content. Youtube too.