Can we be honest with ourselves? Plex kinda sucks. Hard to blame it, most third-party media centers on Android do at the moment. As a lengthy blog post by the developer points out, part of that has been due to Android's inflexibility and lack of a coherent UI in its history. That's changed over the last couple years and now Plex has been rebuilt from the ground up to be a lot more beautiful and a lot more functional.
The new version has followed the Android Design Guidelines very closely and it shows. While most of us here at Android Police are of the opinion that Holo alone does not make a good UI, the addition is most welcome, given the way the old version looks.