I have heard the Meitner professional DAC on a number of occasions but only briefly in my system. The DAD AX24 just sounds more "natural" to my ears. Many mastering engineers have done the direct comparison between the Meitner and the DAD and in every case that I have seen documented they have preferred the DAD.
I'm using it with my DCS 972/974 DXD/DSD digital-to-digital converter until Peter, at DAD, gets his SRC, sample-rate-converter, working up to his "standard" and makes it available for the AX24.
You can see a picture of my AX24 on my System's page on the upper right hand corner of my right hand equipment rack.
The digital interface for 2x-dsd IS NOT TRIVIAL as it has to be in SDIF-3 format.
Trust me you would not be stepping down in any kind of quality. The DAD is the best converter available today; and that is why Telarc studios selected it as it reference DAC for DSD/DXD work. I think that they felt that the Meitner was just as good for PCM.
It sounds like you know what you are doing, but look at the professional forum for head-to-head comparisons from others.