I agree that Megaworks THX 550 is anytime better than the Z-680 cos i compared my Megaworks with my friend's Z-680. Unfortunately, my Megaworks kong after 1 year of usage. Anyway, i just bought a set of Gigaworks S-750 and i'm loving it. Megaworks and Gigaworks differs in terms of tweeters. Mega doesn't come with tweeters where else Giga has titanium tweeters. Thats the difference between these two speakers and most of all, the Gigaworks has better response effect compared to the Megaworks as i've experienced it myself.

Yeah, its stated there as S-700..... Apparently, i'm using 5.1 setup only....
I dont need a 7.1 at a moment.....

Initially, yes.... I tested 7.1 as well just to make sure that every satellites are working appropriately. Well, those 2 extra satellites are just kept in the box as spares.

Nope... I didnt buy the DDTS-100. I bought both from Micro-D (both X-FI XtremeMusic & GigaWorks)...

Well, i didnt change anything. I'll just leave it as its original state.....
So, which speaker set are you planning to get ? Z-5500 or the GigaWorks ?