Audacious: ALSA to PipeWire works, PulseAudio to PipeWire has playback issues
I used the setup described in the recent blog on my Fedora 32 workstation. Performed reboot, and verified with pactl info that PipeWire is configured as expected. Software listed as tested in the blog post (such as Firefox) works for me.
I opened Audacious 3.10.1 to play back some audio files. I used a 16 bit uncompressed WAV file for this test.
When playing back through PulseAudio, the audio has frequent dropouts and does not play back smoothly. I went into settings, changed the output driver from PulseAudio to ALSA, set the HW device to the PipeWire server, and tried both the Default mixer and directly setting my USB device as the HW mixer. In all ALSA tests the audio playback was smooth without noticeable dropouts.
Related to this issue, if pavucontrol is open when I stop playing or switch from ALSA to PulseAudio in Audacious, it pops up a modal error dialog that says "Source output callback failure: Invalid argument."