I was told by the seller when i bought it that the digital engine wasn't upgraded, and the plaque on the back of the unit reflects that. I believe it had some caps and analogue section upgrades.
Don't get me wrong. This GG1 is nice a DAC and does a few things better than the B3. Especially through the midrange - it's purer. But what it lacks is the drive through the bass and mid bass, visceral impact and the sense of a live event. And the most important factor for me, the fun factor. It's a tad boring. So GG1 is nice, but a bit meh. The B3 grabs you by the collar, whispers dirty things in your ear and drags you into the performance.