I think it has more to do with the various source material and what they offer. FWIW I believe the 6 series Vudu app supports DV and HDR10. So whatever movies you might already have in Vudu that support DV should display in DV.
I picked up last years P605 at Best Buy a month or so ago. Just picked up my first 4k BluRay yesterday. It supports both HDR10 and DV. It also came with a vudu code which I redeemed and also is listed as UHD. From what I read it should allow me to stream from Vudu and provide Dolby Vision but I haven't tried it yet.
I can't see my buying a lot of movies physical or digital but a few. Wanted to see what all the hype is about and have a disc or two to show it off. I wanted the Star Wars movie anyway and figured why not get it in 4K. Plus my wife "made" me go to Walmart yesterday. Figured I might as well get myself something while we were there.