Ok, guys quick review for the moment, summary in one word - Brilliant
Painless driver install, control panel is well laid out and works well. Can't see anyone been unhappy with the sound quality. The positional audio in games is scary. You can locate where the sound is coming from whether it's above or below, behind a wall or whatever.
I understand that they are at a different price point, but, The Z is way better than the Xonar DG for everything.
One good feature that I like in the control panel is the speaker setup. You can select from Stereo, 5.1, headphones and stereo direct. You can switch between each one and it will remember what you have them setup as. You can also toggle between headphones and speakers.
I can try to answer any questions you might have, and will try to post more information later.