Just seen HDTV Test put this review up they are one of the best TV review sites on the internet and provide a really good look into this 4K HDR TV cover many aspects which is important for gamers, so I thought I'd link it for people looking to buy this year.
http://www.hdtvtest.co.uk/news/ue55ks8000-201609174362.htm
They confirm the HDR Game mode Samsung enabled is legit and not watered down so very impressive 22ms input lag which is pretty much the lowest HDR input lag you'll find on a 4K HDR TV this year I'd say. Also, they go over the bad points of the TV so people looking to buy can make an informed choice.
Edit: UK to US model numbers (Thanks to Volcano)
KS7000=KS8000
KS8000=KS9000
KS9000=KS9500
KS9500=KS9800
http://www.hdtvtest.co.uk/news/ue55ks8000-201609174362.htm
They confirm the HDR Game mode Samsung enabled is legit and not watered down so very impressive 22ms input lag which is pretty much the lowest HDR input lag you'll find on a 4K HDR TV this year I'd say. Also, they go over the bad points of the TV so people looking to buy can make an informed choice.
Edit: UK to US model numbers (Thanks to Volcano)
KS7000=KS8000
KS8000=KS9000
KS9000=KS9500
KS9500=KS9800