Did anyone ever respond to this question?
There is some stuff on various websites that you can read for insight but nothing to my knowledge that directly compares the work of the two companies with respect to SQ.
Mojo does have some press with Dagogo and Confessions of a Part-time Audiophile and some power cord reviews at Positive Feedback Online.
My mini is currently with Ben at Mojo based on the recommendation of another member here whose opinion I trust.
I just received a Kaia and installed it in my Mini Mac over the weekend. The Kaia I received was very impressively built. I didn't open it, but the case is attractively engraved and painted on the front and the top cover also has "CORE" on it using the ventilation holes to form the word. It is much better looking than anything I saw on the website. It is a heavy, solidly built unit and functioned perfectly after install. I followed the installation video but have installed ram and SSDs in Mini Macs before, so it was no big deal.
The only gripe I have at this point is that the webpage you order from needs to be the Mini Mac server page on the Core Audio website as opposed to the Kaia webpage. Why? The Kaia webpage does not include an option for the internal wiring harness. You cannot install it without one. I ended up chatting with Ryan on a Sunday evening and had to order it that way. I must say, I was impressed that he was available at that time to answer questions. The fact that it arrived without the internal wiring harness delayed my install by a week. The internal wiring harness that I got was the lowest quality offered, which was still $150 (plus $6 shipping-it would have been free if I had it added to the Kaia when I ordered it). This seems excessive for what it is, but the other options (upgrades) are ridiculous for the money. It is quite easy to get up to several thousand dollars for a power supply for a $600 computer if you add some of the wiring and second rail options.
So how does it sound? I have no idea. I made several changes in the system including a Lynx Thunderbolt Hilo. I know the Hilo with Thunderbolt was a big change, even using Apple's stock Thunderbolt cable (I have a Synergistic Research cable on the way). Had the Kaia arrived with the internal harness, I could have done some before and after listening. Unfortunately, I didn't have time this weekend and just had to get it done. The system sounds quite good. I'm not sure what percentage of that is the power supply, but the difference between the stock power supply in the Mini Mac and the Kaia is huge. I'm sure that getting the power supply out of the case must help. I wish I could be more definitive, but I'm not going to A/B this thing by re-installing the stock power supply.
I do have my old Mini Mac that I may A/B with this one, but it is not exactly the same as it is an older unit. If I do, I reply again with the results.