The RME is my initial target but I am overwhelmed by how many features/settings it have. I don't think I can make the most use out of it. Soundwise, I heard some people saying that most dac/amp sound the same, we are just buying its features. So yeah if I learn more about how audio works, I definitely would buy the adi-2.
For day-to-day operation, its no more complicated than any other DAC + amp to use, and you can use it as it is, right out of the box and its default dsettings will be just fine for most things .
But, if you want to, there are a whole bunch of things you can experiment with, loudness, crossfeed, EQ, etc. In addition, the manual is comprehensive, well written and very thorough, unlike the typical afterthoght you get with many electronics; you can download it from the "DOWNLOAD" tab/section on their product page:
https://rme-audio.com/adi-2-dac.html
I don't have shares in RME bye the way, but I have had an ADI-2 DAC for a while, maybe 3 or 4 years, and I'm very pleased with it.