First start-up: the CPU rises to 50%, the interface never appears and it's impossible to kill the process. Logging out the session won't kill it either, you'll have to restart the machine. (Linux Mint (Cinnamon) 21.2)
Not supporting cover art!
The best mp3 tagger I've ever found
Simple and efficient. Musicbrainz and cover search in Amazon support. That's what I needed.
Excellent, intuitive traditional manual tag editor
It takes a bit to really see the power the application has... but it's well worth the curve if you have a decent size music directory.