So, here's my take on all this (and my apologies if it comes across harsher or more accusatory than intended):
I was in the first 10 orders or so as this drop went live, despite what was already a substantial concern over the origin of the IP that forms the hardware basis of the DAC. As a CTH and LCX owner, and with an AAA 789 on the way, I'd obviously like a DAC consistent with the form factor of those to finish off that particular setup. Additionally, given I have DACs of pretty much every other flavor, a ladder/R-2R DAC is something I'd like to add to my collection, much as some purists decry them as 'old tech' with poor objective measurements (whereas I tend to listen with my ears rather than an acoustic analyzer).
I would have liked to have seen a balanced topology, and perhaps MQA support for those of us that have some faith in that format, but be those preferences as they may. There also seems to be a view (admittedly beyond my pay grade) that the PSU and capacitors may potentially have fallen victim to some unnecessarily large cost compromises, but again, at this price point that is what it is.
My big concern, however, is that the still-unsettled genesis of this design presents a huge elephant in the room that, I feel, potentially challenges the integrity of what Massdrop is about. It is clear that, at some point down the line, there's been some degree of cross-pollination between the Airist design and sosolar's. Sosolar feels aggrieved, and I don't feel his concerns have been addressed in any way adequately given the gravity of what is alleged - and "oh, we weren't aware of your design" simply doesn't cut it, it's a cop-out.
I understand that there's only so many ways to design this kind of DAC and that, in execution, they're all likely to look pretty similar. But there's a difference between drawing 'inspiration' from existing designs, as William puts it, and almost entirely cloning the design from schematics, as appears to be the case (the overlay graphic is telling in this respect). Although I'm far from an expert in the (many) intricacies of Chinese IP law, it appears that the engineering and design of products is required to be made publicly available and that clones are, by and large, permitted. That's all fine, provided this is disclosed to us up-front and due attribution is given to the originator, as opposed to the implication that this is Airist's own design and the fruition of two years of dedicated conception and refinement. Similarly, I get that much of the 'magic' is in the logic of what sits on-chip. But as it is now, running this justification as to the similarities simply doesn't, in isolation, pass the sniff test.
I am a huge fan of the concept of Massdrop's collaborations with industry players, both emerging and legendary (especially so with the great Alex Cavalli, with whom I hope there's one final masterpiece still to come). However, in this case, we have a company in Airist, putting out their first DAC (not a problem in and of itself), designed by someone other than their key personnel - indeed, under contract by a third party engineer - and coming up with a design (or, at the very least, a top board design) that is by and large a physical carbon copy of sosolar's - not just in his view but that of a number of other R-2R DAC designers. How, in that case, can this have been a two year exercise? This concern seems to be borne out by allegations that the DAC exhibited by Airist two years ago (and suggested by William to have been the starting point for today's product) was, in fact, of a completely different design (28 vs 24-bit, for a start) that shares little commonality with the current product.
Between William, his third-party designer and Cee_Tee, purchasers of this product deserve a more thorough and satisfying explanation as to its true origin and originality, at a micro level, not just "the end product is different", and leaving a bunch of open-ended questions. Depending on what comes out of that, it may well be that Massdrop requires a similar explanation from Airist and/or its external designer. As it stands, I have a horrible taste in my mouth about the situation, which has challenged my confidence in Massdrop's collaborations and may cause me to think twice about joining such drops in future if this is not resolved in a way that gives us comfort as to the provenance of this design. When we jump on these drops, with the wait times they entail, we're buying a designer's vision and belief in their own product as much as the product itself - in this case the designer is invisible. Airist sells itself as a team of Ivy League whiz kids, yet this product has been contracted out to someone we don't know and who, presumably, will never be disclosed. Just level with us, because something more than "we've never seen sosolar's design" is clearly going on, unless Airist's contract designer has managed to totally defy mathematical probability in, independently, coming up an almost pixel-perfect upper board clone of what Sosolar created in 2015 and has refined since that time. Expecting us to believe that is akin to believing Cyrix came up with an operationally identical CPU to AMD, way back when, 'all on their own', rather than just sitting in a clean room and reverse engineering it, or that the fake Chinese iPhone designers have, in fact, never seen or heard of the real iPhone.
I'd really like to believe everyone has been above board and honorable about all of this, so I can simply enjoy the DAC - but it's fair to say there's a more-than-healthy level of skepticism in the community here, and I think I probably speak for many in saying we need some help and proof to feel comfortable in concluding that. If everything is as it should be, surely an explanation beyond a flippant and all-too-convenient "we've never seen it before" can be given.
More words than needed, but at least it's killed some time on my flight. Back to my Hugo 2 and LCDi4 for the next few hours - two products that definitely have no clones!