Here's the full text of what I posted at the other place.
So, I spent several hours yesterday going back and forth between GO 450 and Herus. Source was a MacBook Pro running Audirvana, and phones used were UERM. I went through most of my standard evaluation tracks, a mix of orchestral, chamber, solo piano, bluegrass, jazz, female vocals, and blues-rock.
I found the differences to be very narrow.
The GO is maybe a little better at plankton extraction. I spoke in the shoutbox yesterday about how the GO brought out the vibrato on held notes in the English horn solo at the beginning of the second movement of the Baltimore Symphony recording of the Dvorak "New World" Symphony (44.1/16 ALAC ripped from CD).
Both are best-in-class at getting instrumental timbres right.
Surprisingly, given the GO's rated output power, I found that the Herus consistently scaled better. This was especially noticeable on two tracks. On SRV's "Wall of Denial (44.1/16 ALAC, ripped from CD)," it was a push at my normal listening volume, but when I cranked it up on the Herus, it kept its integrity; in contrast, on the GO at high volume, the cymbals receded into the background and the drums went from "thwack" to "thud." Similarly, on the second movement of the Branford Marsalis Quartet live recording of Coltrane's "A Love Supreme" (48/16 AIFF, ripped from DVD), at high volume Jeff Watts' drums should explode out of nowhere when he comes in. On the GO, they come in but they don't explode the same way they do on the Herus. On the same track, at high volume the GO adds just a little bit of excessive metallic sheen to Joey Calderazzo's piano.
The one thing that the Herus clearly does better than the GO is capture the innate drive of the music. I mentioned in the shoutbox that in the Dvorak (which is a live recording), the Herus is more "organic;" the orchestral crescendos sound like musicians asking more from their instruments, not like somebody pushing a slider in the control room. The GO is close, but it's a tiny bit more "artificial. The effect was similar on the first movement of the San Francisco Symphony recording of the Mahler First (DSD download). (Aside: the Mahler is also a great test of the alleged high noise floor of the Herus. I don't doubt that the folks who have remarked on it are accurately reporting what they heard, but it's never bothered me).
On tracks that really swing--like, for example, the violin solo in "Macedonia" from the Mark O'Connor album "Thirty Year Retrospective" (44.1/16 ALAC ripped from CD)-- the GO asks you to get on your feet and flop around like a fool, but the Herus DEMANDS it.
For me, with the way I listen and the kinds of music I listen to, I prefer the Herus by the narrowest of margins. The Herus also wins on versatility; you can run it off an iOS device without a powered hub. That said, because I've owned the Herus since the week it was introduced, mentally I've written off the cost of the Herus. If money is an object, the GO wins handily on value proposition, because it costs slightly less than half the price of the Herus.
Bottom line: I could be seriously happy with either, but if I were forced to keep only one, I would keep the Herus.