My first experience with Plex Server running on a Synology DS415 Play streaming content to an Xbox One has not been great (to say the least). First, I had to figure out that there are two version of the Synology Plex Server for Synology: a version for regular users and a higher version for Plex Pass users. In order to support playback on the Xbox One, you apparently need the higher version. To me, this is overly complicated and does not add to a good user experience.
Next I found the experience on the Xbox One sub-par (the interface is slow, load times are long and connection errors appear often). Also the playback of HD content on Xbox One is choppy. CPU usage on the Synology jumps to 98%(!)
As an alternative, I tried the beta version of Microsoft Media Player for Xbox and noticed that 1080p HD content started fast and played fluently. CPU utilization stays at ~30%.
Back in Plex the same content had frequent hiccups (every 10 seconds or so) and lost connections to the server. I figure it is an issue with the transcoding. Is there a way to disable the transcoding on the NAS altogether? The streams play well on my intended devices and I prefer a smooth user experience.