6.01 hasn't helped at all, and I've made the recommended change to the system audio to 44.1k Hz.

I'm listening to it happen as I turn in the level 10 miner quest and viewing the cutscene. The music is stuttering even though there's no voice acting here, just the usual city background music and a few ambient noises from NPCs in the area as well as the system UI sounds when clicking through the dialog.

I haven't even tried combat yet, but I bet I'll be very disappointed when I get to it.