I am no expert at all, but searching after reading our post, and wondering about this topic, I discovered that
this site explains that dynamic is actually better. It also shows a lot of specs that clearly tip in the way of Dolby Vision vs. HDR10+. I only post this for constructive discussion, I don't have the skills to evaluate whose right - just posting that maybe there is another opinion to the comparison!
AVForums, which I do respect, says this:
Dolby Vision can be delivered over HDMI 1.4 or higher, while HDR10+ can be delivered using HDMI 2.0. Although HDMI 2.1 supports dynamic metadata, there is enough headroom in HDMI 2.0 to support both Dolby Vision and HDR10+. Now that HDR10+ has been added to the 4K Ultra HD Blu-ray specifications, there are players that support both formats available from Oppo, Panasonic, and Sony. However there are hundreds more Dolby Vision discs available, and only three HDR10+ discs released to date.
Dolby Vision also has greater support when it comes to video streaming with Netflix, Amazon, Vudu and iTunes all supporting the technology whilst only Amazon currently supports HDR10+. The same is true when it comes to studio support, with Sony, Warners, Disney, Universal, Paramount and Lionsgate all offering Dolby Vision content and only 20th Century Fox currently supporting HDR10+. As far as TV manufacturers are concerned, they all support Dolby Vision with the exception of Samsung who only supports HDR10+.
Here is their conclusion for those who do not want to check out the link:
Dolby Vision is arguably the most advanced HDR format from a technical standpoint, but although it has improved significantly, the lack of content is holding it back a bit. HDR10 has the distinct advantage of having more content available and being supported on the majority of TVs. HDR10+ almost matches the capabilities of Dolby Vision, but is extremely lacking in content, and in the U.S. at least, is only supported on Samsung TVs.
Ultimately, the difference between the two formats isn't that important. The quality of the TV itself has a much bigger impact on HDR (see our recommendations for the best HDR TVs). Although the technology has improved significantly in recent years, it’s still quite early days for HDR. Both formats have the ability to produce much more dynamic images than we are seeing on the best TVs today. The limitation is down to both the TV technology and the way the titles are mastered. We can’t yet reach the 10,000 cd/m2 maximum peak brightness and the expanded 12-bit color range.