Own older Chromecast, great for 1080p TVs, Best buy associate from whom I bought my SUHD TV recommended Ultra for the new TV. It is worth it for 4K even if TV has upscaling. If you do not have fast WIFI or have a lot of wireless devices on your network, the Ethernet is a nice option. Wireless setup can be awkward depending on security settings and type of router.
I would recommend this to a friend
Set up was not straight forward. 1) The Chromecast required an immediate firmware update. However because the wifi signal was not super strong in the room with the SmartTV, the update would not load so I had to move the Chromecast to another TV closer to the router. 2) Then (after moving the Chromecast back to original TV), I did the system setup, and it changed the default feed from cable to Chromecast. I went to Best Buy for advise and was told "that happens" but it should not impact your use of cable. But it did and I could not revert back to the original set up. 3) Also, one reason for my getting the Chromecast was to cast from my mobile phone and tablet to my TV. After installing, I learned that Samsung builds casting into their TV for use with Samsung phones. Since I had a Samsung SmartTV and a Samsung phone, I realized that all the hassle was not worth it. So...after many hours of making everything work, I ended up returning the Chromecast.
No, I would not recommend this to a friend