oh, I forgot, I did use it on a song here, Atlantis, sort of pseudo ducking. Used it for the flange on the vox, to make it low during loud spots but louder during quiet spots. The reasoning was to fill out the quiet vox with flange, to make them stand up better to the dense instrumentation. End result is the loud vocals are drier, the soft vocals are wetter. Not true sidechain compression but done in that spirit.