Sometimes, in certain niches open source software dominates and really is better than the closed source paid software counterparts. Don't believe the (marketing) hype!
Picard is the best. Beets is a little too opinionated.
I've recently started using both though. Picard does the initial discovery and tagging. Beets then adds other features on top like syncing my collection to MusicBrainz, adding lyrics etc.
You can find a brief description of my workflow and some tagger scripts at https://github.com/hashhar/picard-beets-config
I've been there. Got a bunch of files overwritten in the very beginning when trying to create my taggerscript because their names ended up being the same within the same structure.
Thanks for reminding, I'll file an issue against Picard and see if it's possible to add some kind of safety toggle to prevent overwriting.
EDIT: My workflow to reduce chances of file overwrites is to create a staging directory from where Picard can read files and keep the destination directory something else entirely.
So I have something like D:\Music\_TO_IMPORT where new RIPs land (or anything I want to re-import) and D:\Music\Collection which is where Picard writes it's output.
One thing I have seen in mp3Tag but not in others are the easy and powerful batch-processing features (with preview!), somewhat like a DSL.
Want to rename and move all your files at once? go for it. Want to extract Metadata from the file/foldernames? just do it. There are spaces in those filenames but you want them to be underscores? no problem. Remove or add leftpadded zeroes to track numbers? done.
Sadly its only available for windows.
Just to note though, Its more of a tagger than a library management tool. And that is fine, it means it's not opinionated. You can do whatever you want.
There are commits pretty frequently but yes no new releases have been cut it seems. I contribute in my spare time as and when I find annoyances.
I'll check with the maintainers if there's some reason for the hold up.
I use the tools in foobar2000 www.foobar2000.org which are extremely flexible. Not having a separate media manager removes a lot of mental overhead
The fact that Beets intro video renames the MIA album to a folder literally called "____ __ Y __" worries me as to whether its defaults have any level of sanity
MediaMonkey pretty much requires the paid version for serious use. But a) there is a lifetime license (which I bought 14 years ago) and b) new releases are infrequent, they are now at the 5th version in 20 years, so even buying a single version is cheap.
It’s an extremely powerful organizer with scripting and extensions.
A caveat: I just learned that Version 5 was released, a major rewrite, I only checked out the beta 2ish years ago and can’t speak of the quality of this version.
Happy user of Ex Falso here. I agree with your comment regarding gui: I absolutely require a way to verify what these kinds of operations will be doing to potentially thousands of files, and cmdline applications are thoroughly unsuited for that, if they even have functionality like that, which they almost never do.
Picard is great except for one thing - its performance doesn't scale linearly with the number of files in your library. If you point it at a large library, it slows to an unusable crawl.
I don't see why the scan rate should change with the number of files in your library - it really should be fixed.
Just gave Picard a try. GUI takes awhile to get a hang of, but love the acousticID search. I might switch away from EasyTag for this--the fact that it pulls down album art is a great bonus.
Beets is great and powerful but if you overlook something it's easy to mess up your library, but any serious music collector (hopefully) has backups.
Other (GUI) alternatives I've tried:
MP3TAG (free) https://www.mp3tag.de/en/ I didn't see much value over using Picard.
Bliss (paid) https://www.blisshq.com/ Really nice, but was way too slow for me.
MediaMonkey if you're on Windows https://www.mediamonkey.com/
Sometimes, in certain niches open source software dominates and really is better than the closed source paid software counterparts. Don't believe the (marketing) hype!