Whoa, quite a difference in models there...
Well, you get what you pay for usually.
I've read the quality of the gigaworks sets is very good especially the satellites... like as good or better then the Klipsch promedia satellites.
Unless you love boomy bass, it should be a very good set.
Klipsch doesn't really make a low end multichannel set, but I guess the T7700 would fall somewhere in the x-530 to z-5300 range naturally.
(haven't heard either of these creative speaker sets)
I think it's all about how much you want to spend. What kind of deal are we talking about? (price difference to go with the gigaworks over the 7700s?)