I'm actually comparing means to display pictures and video from my Synology RS815 NAS on my Windows10 driven Dell laptop.
Unfortunately Plex performs considerably less well than the Synology apps, in the browser format as well as in the Windows Store App versions.
May I recommend Plex engineers to take a good look at the features (and speed) of the Synology apps? It may well be that you're not targeting the same audience, but nevertheless.