When I heard Plex was coming for Xbox One I got excited because of all the features and possibilities of not having to swap out from the XBO interface to play my media.
I know it's only early days but I've had some Internet issues recently and with that issue also came the big problem of NOT being able to watch any of my local media as Plex needs Internet access at all times when you are a member to check your membership (BTW this should be changed).
Then there's the issue of not being able to use my QNAP Plex Media Server because mine is an ARM version and we probably won't ever have (from what other forums have been alluding to), the version necessary for Plex XBO to connect to.
Then, with a recent update to XBO came their Media Player, the native player for XBO. With my DLNA enabled on my QNAP ARM device it works quite well. It gives me a Recently Added list, and with voice commands it works quite well too with being able to use the names of the files in commands and not using a generic name for each file.
Media Player is quick and simple and plays the files without issue and looks to be a better resolution too.
I'll keep an eye on Plex for updates but at this stage my annual subscription will continue for another 11 mths.
Keep developing and I'll keep checking but for me I'll be using Media Player.