According to an article in The Osborn Price Guide the soundstage (referred to as Stereo Effect) is much wider on Sly & The Family Stones Greatest Hits on Quad versus Stereo.I can say on several of the Columbia Quads I have the LPs play much louder than Stereo versions at the same gain setting.I would think the Quad version would be mastered seperately from both Stereo and Mono and therefore could not possibly be identical.