I found more of a differance due to the hight change then anything else when i installed them. I don't understand how a wobly system like the gia's can increase bass definition, etc,etc.
They definelty helped with noise transfer to other rooms specialy in the bass. But to me that just means they are turning bass movment (cabinet movment) into heat. So I've wondered why they dont lose resolution due to the unstable'ness of the system as a whole. I understand they are (suposedly) directional. No idea, but i use them still even though i'm not convinced they are doing anything for sound quality.