I currently own the Grace m9xx DAC/Amp. I love it but I do know that I want another audio set-up, especially since I have a family member who wants it. I've been really eyeballing the THX AAA 789 Amp and the Airist R-2R DAC. I don't mind the wait into February for shipping!
I know that those two products are very new and there haven't been too much testing done with them, but specs-wise, what are the actual differences between the Grace vs the THX/Airist? What difference of sound signature could I expect? Is there anything that the Grace does better than that stack? The biggest question is if it's even that much of an upgrade. If I need to spend more to get a real upgrade, what would you suggest?