The Vizio looked really nice when i picked one up at Costco. With the extended warranty they gave the tv was such a good deal. But the deal breaker was that the control to calibrate had to be done through an app. My tablet and my phone didn't support this app. So i returned the TV. The TV looked nice, but i think the X800D is an upgrade. Granted, i want to push 4k and HDR through my streams when supported, and just got an Xbox One S just to be able to get some 4k native blu rays.
I do most of my gaming at 4k on my pc too, but keep my desktop res at 1080 for ease of navigation. But all games look really nice.
WIth the Pro it'll be nice to have some 4k games, and HDR coming to some other games i can revisit.
I didn't think much of 4k and HDR. But now that i have seen it on streams, and with Shadow Warrior 2 it makes a big difference.