A friend uses YouTube TV and so do I. He was complaining that when he switches channels when using his Roku Ultra it took at least 6 seconds. I tested this on my Nvidia Shield TV and it took less than 2 seconds. I then tried Mi Box S and it took at least as long as the Roku Ultra.
UPDATE: At the suggestion of Bodycount9 I hooked up the Mi Box S using a USB to Ethernet adapter and it made a big difference in how quickly it switched between channels on YouTube TV. It wasn't quite as good as the Nvidia Shield but it was significantly better than the Roku Ultra connected via WiFi. I then connected the Roku Ultra via Ethernet and found no improvement over WiFi.
1/3rd the price and take 3x longer I'm cool with that.