Not sure if you're aware, but the guy in charge of this, Lynn Fuston, previously ran 3D Audio, where besides his producing, engineering, and mixing work, he did a number of super detailed gear comparison shootouts. A bunch of serious audio folks got together in person to listen to highly controlled live takes through different gear. You could buy CDs of that audio to listen for yourself, think I might have some of those stashed away somewhere.
Short version: He's the real deal, and I'd be surprised if these weren't excellent. They have others too, I just posted this one because it's relevant to guitar stuff.