What is the resolution, and importantly what is the actual bitrate of those TV shows? I ended up dropping plex as a main way of viewing my anime collection because it will NOT transcode at a higher bitrate then the source material. If you have watched anime fansubs you may have noticed they have a lot of skilled encoders who are able to yield good image quality out of low bitrates utilizing tailored settings and slow compression options. So while the native bitrate of 2Mbps of the original file may look great, when plex needs to transcode it will only do so using its own profiles that are 2mbps or less. Not only does this yield a reduction in image quality because now it is a "real time" compressed 2mbps stream, but at around the 2mbps mark anything lower and PLEX switches to 480p profiles only. So in effect I had 720p anime shows that were at such a low bitrate that when plex had to transcode it only allowed 480p profiles. At the same time if the video source is a 480p file, like many of my even older anime was, plex only offers the 480p profiles which are low bitrate, designed for streaming over the internet and to mobile phones and devices. Again this is a significant reduction in quality from the source which while 480p and may still use a good bitrate of 2-4mbps is now forced into a real-time bitrate of 1mbps or less.
This is retarded, plex should not need to worry about bitrate optimization during real time transcodes and instead try to preserve image quality over the network. I should be able to tell it to always use 8 and 10mbps streams to reduce image quality loss during the transcode process. But that isn't how it works so I dropped it. Now I just use a mini PC (Cubi) and play them directly that way.