Besides being an ugly UI, running VLC on the Xbox ONE and using it to access Plex provides a better experience (at least for some content) than using the native Plex app.
Example: VLC can play a VC1/DTS-HD MA MKV (i.e. a remuxed bluray movie) perfectly as is without any transcoding, while the native plex client needs to transcode on the server. It also bitstreams the DT-HD MA audio track to my AVR so that it does the deoding of the audio track.
This is probably a limitation of plex’s design that they want their client to only use HLS/Dash and how they punt the processing to the streaming client provided by the system.
