Nice review. (I'd recommend a spell check)
I got a standard go bar this week and have been testing it against my Dragonfly Cobalt, using my Focal Elegia headphones and iPhone. I found there weren't huge differences in brighter / popier songs, but the go bar was better at everything else.
I'm not that good at all the technical words, but although I really like the Cobalt, the Go took things up a level. Everything seemed a little clearer. Timing improved, as did separation of instruments. There was a bit more snap to the music, making it feel more immediate and live. Ultimately, these things combined made my music more enjoyable, and I felt myself more involved. Maybe, for the first time, I felt I was actually in the studio with the musicians, rather than on the other side with the engineers. I hope that makes sense.