<< I have the SoundBlaster Live Value hooked up with the Z560's.
If I had, for example, the Audigy...would it make a significant difference? could I really tell? >>
You would definitely tell. The Audigy has far superior sound quality. Personally, I would never, ever use sound on an SB Live! The difference in changing to an Audigy, CS 4630 based card, or Philips Edge series is easily recognizable. You would even notice a change by getting a Vortex 1...