The Audio-GD in general (not just the PCM1704) have a sound that is bigger and further back a few rows compared to the competition. This is an aspect that I really like with headphones because it helps to get the sound out of the head.
With speakers, you probably would like the sound direction to go the other way: more forward, closer to you. Think of what the result in the headphones would be? The sound is in your head.
For speaker listening I preferred the Chord QuteHD because it is livelier and more upfront. It's not bad at all with headphones because it has a very good depth in the sound, but the NFB-27 (and now SA-2) pushed the sound fews rows back in depth and the singer would not be that close to my head anymore, for a better overall viewing.
IMO, the headphone amp section should do this "pushing back/forward the sound", so that one can use the same DAC in both headphone and speaker setups without the aforementioned consequences.
Are you including the their Sabre32 DAC's in that?
I find my NFB-7 to be anything but laid back or distant. Just the way I like it