The GS stands for Gem Stone; you get the smaller GemStone speakers and an upgraded universal remote. No difference in sound quality whatsoever. Its a system that will give you better sound than your TV speakers, but dont be fooled by the "surround sound". You will get some sound reflected if your room has 4 walls.
For the money you pay for either Cinemate system, you can get a true home theater surround sound system, with more connections (the Cinemate has just one optical and one red/white analog), and better sound quality.
