@sbank I believe that you may be confusing two models. The current La Scala is the MkII, and I do not believe that there has ever been a MkIII. There is a La Voce S3, which is the latest in that line, but as you suggest the La Scala is widely considered to be a very clear step up in class.
In fact, when I communicated with Aqua before I completed by purchase of the La Scala, they told me that their production capability was "almost saturated by a big number of backlog orders for the Formula, La Scala, LinQ, and a much lower request for La Voce S3."
So, at the time, while the La Voce was back ordered, the company was prioritizing the models that were both very popular and of higher quality.
One other observation that I can make re: the La Scala is that it is somehow able to extract fine details, yet at the time sweeten poorly recorded material. That is counter-intuitive to me, but perhaps it is related to the tube output.
In any case, as mentioned above, I feel no urge whatsoever to make a change, and now pay virtually no attention to articles about other DACs.