When comparing Plex vs AdAway, the Slant community recommends AdAway for most people. In the question“What are the most useful Android phone apps?” AdAway is ranked 2nd while Plex is ranked 20th. The most important reason people chose AdAway is:
Use the hosts files to block ads, so it works for everything.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Supported on many devices
It's pretty hard to find a NAS or STB that doesn't support Plex.
Pro Accessible via web browser
A modern web browser is enough to get everything Plex has to offer.
Pro Added lots of media databases
Metadata for media files will automatically be updated by using media databases. This provides posters, movie trailers, descriptions, information about actors, etc.
Pro System wide blocking
Use the hosts files to block ads, so it works for everything.
Pro Doesn't consume CPU time or memory
The app updates the hosts file periodically but doesn't need to run in the background in order to block ads, which is especially convenient for older phones.
Pro Can use systemless host
Can be used without modifying the system if rooted with magisk.
Pro Can use custom host files
Lots of people and keep their own updated host files used for blocking ads and ad away supports loading them in or even adding their source for autoloading.
Cons
Con Needs registration
You need a PLEX account even if you use it on your local LAN.
Con Proprietary software
Unfree software.
Con No gapless audio-playback
Plex still does not support gapless playback of audio files such as mp3 or FLAC.
Con Playback error: This server is not powerful enough to convert video
More hardware requirements on Plex due to a useless/non-intuitive transcoder. When using lower spec hardware (eg SBC) Plex will not transcode or play HD+ videos. When compared to other packages (eg Jellyfin which transcodes nicely using FFMeg), Plex falls short on video playback and transcode settings to get videos to play (fastest/lightest option still fails).
Con Needs root (by design)
Needs root to update the hosts file.
Con Won't block same domain ads
Because the host file can only redirect domains, if the ad and content are on the same domain the ad will be displayed.