75" Samsung QN75Q80TA QLED 4K UHD HDR Smart TV + 4-Yr Accidental Warranty Expired

Is Dolby Vision important? Yes and No.
Yes, it without a doubt is the best implementation of HDR available as it's technically superior to the other formats. It's hardware based and makes numerous adjustments to the TV that many manufacturers don't let you change. The scene by scene or frame by frame metadata on the disc are interpreted by the chip, and are made to try to compensate for the shortcomings of TVs to give the best picture possible to get the closest possible picture to the creators intent.

After reading that I'm sure you're now scratching your head wondering why I would also say it's not important. A few reasons. While it's currently more prevalent than HDR10+, most home releases are also not in Dolby Vision. Speaking of HDR10+, it also offers the dynamic metadata that Dolby Vision provides. It is not hardware based, so it will work the best in Samsung devices but is rolling out on more and more devices. While DV can be mastered to 12bit color, no TV can display it, so they're both limited to 10bit color depth. Dolby Vision also becomes slightly less relevant when considering that most high end TVs have their own tone mapping algorithm to try to provide adjust.ments to standard HDR10 content to further enhance the image quality. Finally, it can only do so much to enhance image quality. If you do a "blind test" of say a Vizio M Series Quantum next to a Samsung Q90R I'd put money down that the majority would prefer the image quality of the Samsung over the Vizio. There's a reason Rtings recommends Samsung over pretty much every other LED despite the lack of DV support.

Won't buy a Samsung until they support Dolby Vision.

I bought a tv from these guys recently and got a cps warranty. They have a horrible reputation online and I hope I never have to use the warranty.