Another Plex convert here, it's very smooth what you can do with it, and
I have always had some issues with Pis. I don't have a TV but a
projector, so I have an interesting setup, with plex server running on
my HP Microserver and a NowTV box running plex. Not many people know
but the NowTV box (£10) is basically a 720p roku which means you can
sideload a single app onto it as well as use it's normal features. Plex
has a build for roku and it works really well, albeit the nowtv remote
is a little "limited" (13 buttons!), it is IR and I got a multi-remote
so I can control my projector, hifi, nowtv, blu-ray, hdmi
switcher/splitter(optical audio to the hifi) and sky box all from the
remote.
Anyway, there's a few more things for you to think about.
Cheers,
--
Martyn