Regarding technical specs, have you ever looked at the manual? That's how you start comparing products.
The value for SNR is also the dynamic range of the device.
ADI-2 Pro FS R BE, see chapter 33:
https://www.rme-audio.de/downloads/adi2profsr_d.pdf
https://www.rme-audio.de/downloads/adi2profsr_e.pdf
ADI-8 DS Mk III, see chapter 12:
https://www.rme-audio.de/downloads/adi8dsmk3_d.pdf
https://www.rme-audio.de/downloads/adi8dsmk3_e.pdf
You can integrate the ADI-2 Pro easily using any of the AES or ADAT ports, I described it here:
https://www.tonstudio-forum.de/blog/Ent … our-Setup/
The ADI-8 DS Mk III can also be connected easily using ADAT.
From the product pictures, the product description on the internet and the manual, it is obvious that the ADI-8 DS Mk III does not have a headphone amplifier. I would trust the manufacturer's manuals more than any civil servants who write any other documents for import regulations of your country. Who knows where they got the info from or how many mistakes were made by copy/paste from other product descriptions of similar products.
The ADI-2 Pro and the ADI-8 DS Mk III are both converters, but they are different in terms of the number of connections and functions. Especially, the ADI-2 Pro has a lot of special product features that go beyond the usual characteristics of a pure AD/DA converter, which has its price for the smaller number of channels.
Therefore, I wonder what your requirements are and why you are comparing these two devices that differ in many respects.
If you had compared the ADI-8 DS MK III with the M-1610 Pro, that would have been more conclusive.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13