I tried to setup Plex and it was just about the most god-awful experience I've ever had. It was unnecessarily complex to accommodate their cloud infrastructure setup.
Installing Jellyfin took like.. 2 minutes and I've had no issues since.
Only thing I don't like about Jellyfin is the metadata engine, which I have disabled and just use TinyMediaManager and save everything to .nfo which is picked up by Jellyfin immediately. Works great.