I have recently purchased the RME ADI-2 DAC FS, and would like to give my own impressions, especially a few points I think haven't been mentioned yet.
First, a confession: I was a Schiit user. I have been off the Schiit for 2 weeks now. I want to thank Amir for the encouragement that he, unknowingly, gave me through ASR. Like so many others, I was lured into Schiit because I liked how easy and inexpensive it was to start with Schiit. Spend a hundred on the DAC. Spend a hundred more on the headphone amp. And one by one I was sucked into it. Or, more precisely, suckered into it. Before I knew it, I had spent more than 400. At the same time I was into Schiit I became aware of Amir's criticism of Schiit, but dismissed it because, let's be honest, the takedowns of Amir at other places were really funny sometimes. Also, at the time I did not see which alternatives Amir could offer other than some questionable Chinese products. So in the end I had this setup: Modi 2 Uber (which I later replaced with the Modi 3), Magni 3, Sys, and it still didn't work alright. High sensitivity to hum and coil whine, ground loops, external power supplies that ran hot even when the Schiits were turned off mechanically, noise creeping in through USB, and sometimes the Modi 3 would just mute on my Mac and not produce any sound. The whole stack was connected to my active Yamaha monitors, which meant going from unbalanced cinch out to balanced in, which gave me other problems.
I pulled the plug, and replaced all of it with a single RME ADI-2 DAC FS. Now I run one machine over USB to the RME, the other through optical, and output through XLR to the Yamahas. Which brings me to my main points:
Typical active monitors - and most people with a DAC/amp on their desktop will probably use actives - have balanced inputs. The ADI-2 DAC has balanced outputs, which means cable length becomes a non-issue. Many competing products, and I use the term loosely, have unbalanced cinch out only.
The ADI-2 DAC has an excellent equalizer built-in. Frequency manipulation happens in the DAC at its internal resolution in near-real-time. Again, if I were to use a Schiit DAC or similar I'd have to get either a separate equalizer, or do it in the player software, with unknown precision and latency.
The ADI-2 DAC also gives me a built-in tool to check for bit-perfect playback. Just download the test files from RME, and play them out, and the ADI-2 DAC will auto-detect the samples and tell you on the display if the samples arrived in the DAC unaltered. I haven't seen anything like this from the competition, certainly not from Schiit where I'd be flying blind. By the way, the test file samples range from 16 to 32 bit.
The ADI-2 DAC has a very nice LCD display. What's even nicer is that it will display information like the currently set clock source, resolution, volume, and channel balance. Again this is something where you'd be flying blind with most other competitors.
So apart from the RME device performing much better than the competition, we also need to look at the actual value per dollar spent. Or, to reverse it, how much would I have to spend to get a comparable setup from other vendors, e.g. from Schiit?
Something like this (and I'm being very generous in assuming that performance would be comparable, which it is not): Schiit Gungnir ($850) plus Schiit Magni 3 ($100) plus Schiit Loki ($150) = $1100. And then I still don't have the display, the IEM out, and the profile-based customizability.
And even if I started from my current stack and expanded it, I'd end up as follows: Schiit Magni 3 ($100) plus Schiit Modi 3 ($100) plus Schiit Sys ($50) plus Schiit Loki ($150) = $400. And this stack will definitely not give me an approximation of the sound quality or flexibility or connectivity that I get out-of-the-box from the ADI-2 DAC.
In the end I think RME identified the weak point of much of its competition: assembling your own stack makes little sense for the majority of users who really want to end up with a setup where they have multiple inputs, headphone amp, balanced out, and user presets. RME correctly engineered it into a single device that you set up once, and then be done with it for many years because it just works.
I'd also like to thank Amir for not only pointing out, repeatedly, the deficiencies of the competition, but also for doing in-depth measurements of RME products and for pointing out a real alternative where I, as a former user of "hip" made-outside-China products, get real value that not only sounds good but also measures as it should at its price point.
A final word, and an offer: the ADI-2 DAC is not perfectly immune to USB noise and ground loops. If there's interest, I can write up how I solved those.