As a former owner of the 2016 M70-D3 and a current owner of a KS8000, I couldn't disagree more on your assessment; it's more complicated than what you're painting.
My post you're replying to was intentionally high level, with explicit notation of what is my opinion and what wasn't. In addition, the M-Series isn't even in the same tier as the KS8000, again, as I relayed. The P-Series is the KS8000 competitor.
Though let me respond to your points.
One, Vizio's UI is nonexistent while Samsung has one of the best integrated user interfaces out there. My KS8000 can read and label all the inputs, integrate with my DirecTV receiver so I get show previews, and a really slick universal remote that has voice control built into the remote. Vizio does the whole GoogleCast approach which means you need to beam content from other devices instead of using a built in app, not a fan of having to search for a tablet to control what I'm watching.
I much prefer the Chromecast approach. I needn't ever worry about the TV's apps getting out of date. In addition, I can Chromecast from *any* of my capable devices. And once streaming, the remote can take care of the rest. These are all arguments based on opinion. Though you imply that Vizio does not allow one to change input names, which I am absolutely befuddled by.
Two, Vizio's 2016 line has a bunch of problems with various 4K HDR sources. My M70 would routinely have video and audio dropouts, and Vizio keeps releasing software patches that create new problems. As of 10 days ago, the M Series line couldn't show 4K HDR movies or HDR gaming from the Xbox One S, which is unbelievable.
Anecdotal evidence to the first part and not 100% correct to the second. Anything in your HDMI chain could have caused the A/V dropouts, even down to the cables. The M-Series is perfectly capable of showing 4k HDR movies, streaming, HDR10, Dolby Vision, and UHD Blu (including the Xbox One S!). The Xbox One S gaming HDR comment has already been discussed above. The problem is getting fixed, so there's not much else to go on about that.
Three, speaking of being future proof, Samsung is much better positioned for that because of their One Connect platform, allowing owners to upgrade their HDMI ports to support future standards. Dolby Vision may be a superior HDR format, but HDR10 has wider adoption and appears to be positioned to win the format war since its free, whereas Dolby Vision requires dedicated hardware and licensing fees. Also, Samsung has a better track record of continuing to support their sets. I have a 2015 M-Series that didn't get much software support in new apps. On the flip-side, Samsung pushed firmware to 2015 sets to support HDR when they didn't have to do that.
You're making some very sweeping presumptions and doom-and-gloom predictions about Dolby Vision. Considering Dolby Vision is the format cinemas have adopted, along with Samsung & Sony being the only big names to not support the format, I'm finding it hard to understand where you're coming from. The content is there and it's growing. This isn't a format war akin HD-DVD and Blu-Ray, but rather like Dolby and DTS audio formats.
Also, the One Connect box is a great idea!
Four, input lag on Vizio HDR content is not "slightly higher", it's 3x higher than what Samsung has accomplished on the KS8000. I know the Vizio CTO is on record tying to find ways to reduce input lag, but it is what it right now.
I, too, can play with numbers and make them seem worlds apart. The facts were stated, end of discussion.
Don't get me wrong, Vizio is not a bad brand, but I have zero confidence in their ability to get their software situation together after going thru 3 firmware updates on my 2016 M Series. To their credit, Vizio issued me a full refund for the set I bought after owning it for 4 months based on my dissatisfaction.
Ah, there it is. You have an axe to grind.
As someone that has had the opportunity to own both sets this year, Samsung's KS8000 is just an all-around, more polished and elegantly designed set, from top to bottom.
You are entitled to your opinion. However, you're challenging the differences between the two sets with a bit of FUD.
I'm not trying to be the Vizio defense force here. I have openly admitted faults in Vizio's line and I have praised the KS8000. I just think you missed the mark on some of your responses to me.
They are evenly matched sets. Where one exceeds, the other is serviceable, and vice versa. They end up being a wash at the end, with either model lines being great purchases.