I'd rather use buggy software under heavy development if it has has technical superiority, instead of old, maybe unmaintained one.
For exampe Audacious devel over XMMS, E17 devel over anything else, iwlwifi over ipw, OSSv4 over Alsa and so on...
Anyway GTK1 will be dropped by most distros in just a few years, just like motif or tk, so one day you'll have to use something else whether you want it or not. Audacious is a nice not-jukebox player, close (but not identical,maybe better) usability-wise from what xmms was. You should eventually try 1.4 when it will be released, I'm sure it'll be a pleasant surprise.