Just wanted to share a recent experience. My version 1 died but RME support is just world class (same great service at work and home). Long story short, I now have version 2.
I updated the firmware, loaded some EQ curves for the HD650 using the Remote ADI-2, and did the bit test to verify foobar was OK. I enabled loudness (my favorite RME feature! this alone is a reason to get this dac). I tried to select the best filter for my taste and settled on "Sharp".
I haven't listened to the RME with headphones in a long time, cause it was setup for my main system. Anyway, I hooked up the HD650 and hit play.
OH MY... this is what high fidelity is all about. Between the quality of every section and the rich features, you just get the recording as it was intended. I'll limit the subjective talk to that
.
My only worry is that it makes me wonder about keeping this in the office and getting a 2/4 for the living room. Looks like the 2/4 could do bass management for a subwoofer. And for my geeky side, it would be easy for me to measure the RIR,
compute some parametric filters in Matlab and send them to the dac (manually, with Matlab MIDI or dump an adieqpr file for their remote app). With the features, the clear documentation, and the open format (text-based settings file, open MIDI protocols), this is just so versatile, with no tradeoffs on audio quality.
RME happy camper here