Still burning in the GT7B from GS Audio, and their bass response is growing better and better as time goes on. I'll make a proper thread for it and post a more thorough review once they've got a few dozen hours on them.
Brief impressions: details, details, details. These things are incredibly resolving, particularly in the upper mids and treble. I'm guessing it'll improve in the mids and bass as those drivers loosen up a bit. The soundstage is a bit wider than on the TRI Starseas and CCA CKX and the timbre in the mids and highs are on par with the Starseas, if not better. These things certainly aren't bass monsters, at least not yet. I'll make sure to repost if that changes in the future.
Finally, these things are stupidly easy to drive. You can power them from just about anything and not be terribly disappointed. They are also incredibly comfortable in my ears despite my misgivings about the winged shell design. They also isolate extremely well.
I ordered mine with the shell design from the SD3 because I love the purple on purple theme. Side note, these use a recessed 2-pin connector, so you may want to request a shell modification to a flush 2-pin if you want to easily use them with Bluetooth adapters. Despite that, these things are absolute stunners!
Edit: if you get a set from GS Audio with a DD in it, consider burn-in to be compulsory. These drivers a very fresh and still a bit too stiff. Make sure to give them a thorough running in before making your final assessment. Even with only a few hours of active burn-in, they've loosened up noticeably and the bass response is filling in well.