Again, I suggest testing the idea that it's the WIFI that is causing most of your problems. Some have posted that it should not be an issue but they can't know your setup, how many people are simultaneously using bandwidth, etc. Your suggestion that sometimes it's working and sometimes it's not sounds like sometimes you have access to more bandwidth and sometimes others may be accessing the bandwidth. Are you noticing a pattern of perhaps others getting home from work or school and getting online and then these problems showing themselves more readily?
The easiest way to test my guess is to run ethernet cables through your home so that you have a wired connection from computer to router to
TV. For a test, it doesn't matter where these wires run- even middle of the floor- as you are just trying to see if this is a cause or contributor to the problem. It should be relatively cheap to test- all you need is some ethernet cables long enough to make the direct connections.
A pure connection like that thoroughly tests the idea. If it turns out that things are much better with a wired connection, then you start looking for ways to re-route the wires without them running across the floor: can you get them into the walls, up into the attic or down under the floor and then down or up to your
TV? And/or that is the point where I would experiment with the powerline options if there is no good way to run some ethernet direct.
What I wouldn't do is interrupt the "pure" connections with the powerline connections for the testing. That's introducing variables that you don't really need to mix in here to see if it is a bandwidth issue.
If you try the pure connection and the problem persists, you'll have eliminated my main guess and can then focus on other possibilities. For example, the Mac Mini idea (with hard drives attached to it) replacing the
TV as your Plex player.
