Back in the day I had an xfi extreme music, and a headset with 3 speakers in each ear for real 5.1 surround sound in a headset. People though I cheated all the time in COD and Medal Of Honor, because I would turn and face people through walls and buildings, I could be ready for them before they turned corners. It was really just because I could clearly hear their footsteps and gear gingling from far away. With regular software/mobo audio this doesn't happen at all.
Since microsoft removed the audio HAL, hardware accelerated audio pretty much died instantly.