If your phone is your main conduit to streaming audio and video on the ‘net, the Chromecast Ultra is a simple, high-quality way to get it up on your big TV. If you want to kick back with a remote and browse for things to watch, there are better options. The lack of Amazon Prime Video support and a dearth of format/setup/troubleshooting information are annoyances, but not dealbreakers.
The latest Chromecast works a treat with 4K and HDR, but it’s a little pointless.
There’s almost no refuting it: Chromecast Ultra offers one of the best values for streaming video devices for 4K TV owners. There’s not as much benefit for the 1080p crowd, but if you’re looking for powerful, fast streaming in a device the size of a wafer for your brand-new UHD TV, there’s no better place to find it than Chromecast Ultra.
Google's premium Chromecast quadruples the pixels for double the money, but lacks the bells and whistles of other high-end steaming devices.