Dolby Vision has been adopted by film studios like MGM and Universal, along with streaming services including Netflix, Amazon and Vudu. TVs bearing the badge are supposed to be up to 40 times brighter than standard TVs, have better blacks, expanded contrast and 12-bits of color per pixel, equating to over 68 billion colors, compared to just 16 million for a regular TV.
Both the Roku C- and P-series have 4K Dolby Vision and HDR10 support, along with 4K "Creative Pro" upscaling, the latest Roku OS, new LED phosphors that supposedly deliver better colors, HDMI 2.0a and HDCP 2.2, 802.11ac wireless and ethernet. However, the C-series is attacking the higher end of the market with a slimmer, more contemporary design and also has "HDR Dynamic Contrast" that optimizes contrast by scene. That model ranges from 49 to 75 inches, while the largest P-series model is 65 inches. (Prices haven't been released yet for most models.)
TCL also launched the 2017 S-series, with regular HDR but no Dolby Vision, ranging from 43 to 65 inches. That lineup also packs built-in WiFi, three HDMI ports and, of course, the Roku streaming features. All told, CES 2017 represents a big new step for the Chinese company, which, despite being the third-largest TV manufacturer in the world, is little known in North America. Whether the picture quality can stand up to rivals like Samsung and LG remains to be seen, but we'll try to get a closer look on the show floor.
https://www.engadget.com/2017/01/04/tcl-adds-dolby-vision-hdr-to-more-of-its-4k-roku-tvs/