I don't know if it's a bug, or if this is done purpoesly by design, but the audio pans way too hard. Something just barely off-center to the left or right on the screen is panned hard left or right. It's annoying as heck, and it detracts from an otherwise stellar audio experience.
Agreed, it's terrible. I've submitted an official problem report about it to Blizzard Support, but I'm unfortunately discovering all I get is 'sorry' and 'why don't you post on the forums about it'. Let's see where this goes.