Not any personal experience with it, but a quick Google is showing that it's an entry level 4k TV. It doesn't get very bright, so HDR isn't going to be impressive, but it does have low input lag, and good blacks, so it's not terrible.
I'm so tired of my 70" Vizio being a piece of shit, that I'm tempted to switch to this one myself.
Samsung NU6900 Review (UN43NU6900, UN50NU6900, UN55NU6900, UN65NU6900, UN75NU6900)
The Samsung NU6900 is an alright entry-level 4k TV. It's available in a wide range of sizes with budget-friendly prices, and it provides okay overall performance...www.rtings.com
The V656-G4 is supposed to have Local Dimming and is only $40 more at Best Buy.