I can tell you that the Z-680 is now out of production, with a new model the Z-5500 to replace it. So you may want to hold off your purchase until you see it. A photo from Russia has leaked out of the new system:
You want to look at the Klipsch Promedia line and the Edifier S5.1 system too.
I want to buy a surround sound speaker system for playing music and watching movies on my computer. Is there any advantage to buying speakers made specifically to be hooked up to a computer (i.e. Logitech's Z680) instead of HTIB speakers?
Also, Logitech's Z680s come with a small hand-held A/V reciever. Would I have to upgrade my $20 SB Live Value soundcard to something like an Audigy ZS Platinum Pro to be able to get 100% of the Z680s potential performance or would the mini A/V reciever do the job of a nice sound card?
Finally would I have any problems setting up an HTIB system (I'm looking at the Panasonic SC-HT05) to accept the output of my computer? Again, would I need a nice soundcard to get 100% of the speaker's performance capacity or would the A/V reciever that comes with such systems do the job the soundcard would normally do?
Here are the links to the Logitech and the Panasonic SC-HT05:
Logitech Z680: http://reviews.cnet.com/Logitech_Z_680/4505-3179_7-20720043-2.html?tag=top
Panasonic SC-HT05: http://reviews.cnet.com/Panasonic_SC_HT05/4505-6740_7-30898391.html?tag=topprods
Your help is very much appreciated,