Guttenberg only discusses equipment that he already likes if that is what you mean.
that part is fair. He had said it and explained why there is no point in reviewing what he does not.
Disclaimer: I don’t like his reviews. I honestly don’t understand his popularity. The words he is using, the methodology (if any), it’s so vague and inconclusive, I learn nothing. It’s a tough job, I admit, reviewing stereo equipment, but Erin’s AudioCorner is pretty good, and a few others, who were born without the ability to BS and everything they say is relevant, they say it for a reason, for what they want you to know, not for what they want you to feel or like or believe.
I also think he talks down, he has a lecturing style that I don’t get.