A couple years ago, I set up a FreeNAS box to solve the problem of, "the file I want to work with is not on the machine in front of me." Once set up, I also wanted a media server so I could watch stuff on the TV in the living room. Many of the comments in the FreeNAS discussion fora spoke well of Plex, which is available for FreeNAS as a plugin jail. So I installed it and gave it a spin.
"WRONG!" exclaimed I. The whole point of a local media server such as Plex is for all media-serving code and resources to be hosted locally on my server hardware. The moment you start reaching outside the LAN to do anything, you are no longer a local server.
This discovery basically shattered any alleged positive value Plex may have had, since its primary function -- the basis on which it was sold to me -- turned out to be a lie. I promptly uninstalled it.
Now, it seems Plex has dropped the pretense altogether, and are just another disk farm outside my control. Good luck with that, guys; I'm sure you'll be able to beat Apple, Google, and Amazon at that game.