flat4, seeing as how no one else responded to your simple inquiry, though it's been an 18 hour day, I humbly submit that the correct answer is "everything". I haven't found a significant parameter of sound quality that is not enhanced by Schroeder Method. It effects dy�namics, tonality, cleanness/defintiion, soundstage, etc, etc.
The elevated sound quality has now become my new norm. I can't imagine ever going back to single IC preferentially. You won't believe your ears how much more sound quality is innately available that has been squandered by single IC. The industry and hobbyists have been using an insipid method for decades. Pretty sad how compromised sound universally has been considered good. At least I now never have to suffer that in the future with most gear.