I've been disappointed in the MiBox up into a few minutes ago with it's inability to handle 4k Bluray rips. Tried everything I could think of until installing the Kodi 18 Alpha today. Now I have the ability to play 4K UHD with HD Audio on my system. I thought it was just the MiBox being underpowered turns out it's software related after all. Who Knew?
1080p and 4K Kodi use on any Android TV device that cannot do Auto Resolution switching is a bad idea.
And that includes the NVIDIA Shield as these guys complain about:
https://forums.geforce.com/default/topic/910766/shield-tv/disable-upscaling-in-nvidia-shield-4k-uhd-/1/
Android TV is all about Apps convenience and usability, not top spec Kodi audio or video quality.
Demanding 1080p / 4K Kodi users actually run Linux/LibreELEC machines to avoid Android OS limitations that affect proper Kodi usage.
Netflix - 4K UHD has a relatively low HEVC streaming bitrate.
Raw - High Bitrate 4K UHD with HD Audio over WiFi - ROFL - good luck !!