Here is mine; got it since 4 days
To sum up, let's say, as I'm no expert at all, that it makes the whole thing much better: in terms of amplification and SQ; I'm not such a fan of the "surround" button as I don't like the original sound to be transformed... The mariage with my SH Amperior is pretty good: actually I could ever use the Iphone without the Go Dap X because of the very low impedance of these headphones, but the Dap makes it better after all; The good thing is that I can carry the rig with me in my pocket (would have prefer right angled cable btw...): it's not this heavy and very thin actually;
The surround function can be appropriate for some kind of music I guess as the bass option (why is it so weird/complicated to activate it?) which I dont need with these HP.
I'm not found of the battery indicator: you don't really know for how long your Dap will run yet...
It's ok to syncronize the iDevice too to your computer via the Go Dap.
About the cable I'll run some tests between the toxic one and the looooonnnng Apple original one to see the improvment (or not).
Plus I did not give a try to the USB Dac function either yet.
AFAIK It is a really good product (well built) for the asked price; all I can say for now!!
PS: dont know about the black unit; red one is ok for me: quite clear even If it's never enough for me...
PS2: have to thank VentureCraft for their great service and for having answering all my stupid questions.
Did you complete your review of the toxic cable?