You know, everything I have ever done has "problems". Since I am the release authority on my products it behooves me to make sure any of those are so minor as to be inconsequential. If I fail in that regard, it will cost me time, trouble, and money. So minor, in fact, they must be reduced to the level of imperfections as a design imperative. If called out on those "imperfections", my first response will probably be like it was 30 years at Theta, where I would tell them to go buy a phuckin' anybody else's DAC. All these years later, I am still doing the best I can for the most people. No matter what I do, I can't build an every person's DAC or digital audio thingy. It is inevitable that somebody out there is going to tell me I'm full of Schiit and believe it as well. Way back then, Theta was the first company to go upgradable. Everything Bifrost and up continues so today at Schiit. Every now and then someone will tell me how much he spent on Bifrost upgrades. You want a better sound earlier than others, that's why you go upgradable. You don't like it, buy some phuckin' DAC where you have to throw the whole thing away. Then watch the Accu-Jack model I resale crater when the Accu-Jack model 2 comes out. That is not as hostile as it sounds, I just have to pick a path and stick with it - which I have been doing so for decades now.
So here comes another benefit of upgradable gear which has nothing to do with earlier rumors on this thread: from time to time we make trivial and minor improvements to our gear. That's why an Yggy flushes down all of the old Theta gear. In 30 years you learn stuff. Problem is most of those upgrades do not justify a trip back until we have something of major consequence to upgrade. $75 worth of shipping for a $2 part? Nah. All good things come to those who wait. You will be able to upgrade. You can bet most other makers of DACs do as well. With no upgrade path, however, you will be looking at the resale of the Accu-Jack 1 unless you are psychic.
One of the reasons I designed Mimby was that it will result in upgrades all of the way above it up the line. This is true even if the Mimby itself is NOT upgradable.
So that is one design path I follow; it is the best I know how to do, even yet today over thirty years later. I am very grateful to have so many happy clients today. I have them all to thank, which I do not do often enough.