Still pretty bad. Firefox can't freely select audio devices per stream. Chrome has some kind of unbeatable adaptation that makes latency fluctuate.
enumerateDevices() should enumerate audio output devices (feature behind pref): https://bugzilla.mozilla.org/show_bug.cgi?id=1152401
Enable by default setSinkId pref: https://bugzilla.mozilla.org/show_bug.cgi?id=1498512
Alex Chronopoulos: "We keep it off because it does not work for everything. It works when we playback a file but not for webaudio or WebRTC. We want to add those too and we keep it off till then."