My friend and her boyfriend came over and he brought his 360 that had an intercooler hooked up. All I can say is damn. . . . . . we were playing Gears and we had to turn up the TV a lot just to drown out the sound and we were playing on a 60" HDTV too.
We got a kick out of turning on my PS3 right after we were finished playing and you couldn't hear a damn thing. Since I don't have one, I can't give any fact on it, but I've heard that the intercooler, apart from making the 360 louder, can also meltdown your 360.