I chose this configuration rather than running plex in the cloud because a) don't want to pay monthly forever for something I use a few times a week; b) less wasting power and c) this at least theoretically can work during an internet outage (though plex authentication may make this difficult). I configured the HDD to spin down after 20 seconds of no r/w, so the whole thing draws very little power while idling (or so I assume).
The major limitation of this setup is that the pi cannot handle video transcoding. As long as I transcode to something the Roku supports natively this isn't an issue: transcode once (on my laptop), put it on the Pi, play whenever. I have yet to script this process but that's my next step in the project.
It will probably be a year before I realize any cost savings (a friend pays CAD20/mo for a hosted setup which also handles on-the-fly transcoding), but, well, it's a simple server and I just wanted to do it myself, gosh darn it!
