I already started migrating to Emby. I have an LG G4 and an a bit older Samsung, no real updates to both Plex-apps since like forever.
It is a bit more work to migrate, as the media mapping is a bit weaker. But for me around +85% were detected fine, the webOS app works smoothly for my requirements!
As I have Plex Lifetime, I keep it as backup for the very few occasions Emby is not as good, but its worth it.
As I honestly really like Plex in general, I might go back to it if they fix it sometime… but if Emby keeps up, I maybe wont.