MP3 and ID3 library/module recommendations

[p.]

Wondering what experiences people have had using various packages for
extracting data from and manipulating mp3 files. Specifically, i need
to get a song duration, which as i understand it, you extract from the
framesets, as well as the typical id3 stuff like artist, album, song,
year, etc. Ideally, i'd also like something that converts audio files
to mp3 format.

Looking on the the python package index, I see the following:
- eyeD3
- PyMedia
- hachoir-metadata
- libtagedit
- mutagen

Any others to consider?
What are peoples comments on these?

thanks all,
p.