If anyone's interested in a low budget but honestly great 4k HDR TV, I'd suggest looking into the Hisense M7000 series.
I've had this set for over two weeks now and I have to say it's marvelous, as far as color reproduction and black levels go. Input lag is good and while not great as some higher end samsung, gives me no issues while playing FPS games.
I've waited for the avforums review in order to put it here, and now that it's out and it
confirmed my positive impressions, I'd say give it a chance if you're in the market for a new tv (and you're not in the USA, where the discounted price of the KS7000 effectively makes it almost a direct competitor to the Hisense)..
I should mention that, while it's an HDR tv, it's nowhere near 1.000 nits, it's more in line with the Sony Bravia XD80 lots of folks have here, so around 300 nits.
Also, the review mentions 38 ms of input lag,
another one 36 ms and another one (can't find the link, will post it as soon as i find it) 32 ms. I don't know what's the deal here, but as I said, I've been playing games that require fast reflexes with no issue.
EDIT:
here's the other review (FRENCH)
Also, it may not have all the nits, but black level is good. Like, really good, and panels generally don't have much bleed. Some folks over at AvForums even migrated from Ks7000-8000 Samsungs because of better panel performance for light bleed, uniformity, etc. (some did the opposite, it really boils down to what you prefer, either nits or black level.. and input lag, of course, if you're picky about it, especially if you game extensively in HDR.).
EDIT:
Also reading the
review topic here might give you an idea of why it could be preferable to, say, the KS7000 (8000 in the US).
My two cents. Happy gaming, everybody!