I agree fully to this - at least in my experience.
I have been away from Head-Fi for awhile, but I've recently purchased and received the Pontus II from Vinshine Audio, and I've had a couple extremely enjoyable headphone sessions. I've been using the internal DAC from my Innuos Zen Mini + LPSU for a year or so for my headphone and 2 channel set up. The internal DAC is likely a $50 part that is there for the functionality of connecting an amplifier directly to the server.......but it hasn't been shown to be rubbish when compared to my friend's Chord Dave or Holo May or Chord Qutest.
I met a fella at a recent Audio Advice 'show' at the Hilton in Raleigh, NC - and he introduced me to the Denafrips brand.....he had recently downsized homes and his system. He replaced a costly DAC (can't recall which one at this time) with the Ares II, and he was very impressed with the sound. I didn't have a chance to demo his Ares II, but started reading / watching reviews.......that got me to the Pontus II.
I purchased through Alvin at Vinshine Audio, and the customer service has been exemplary. Through the ordering process, tracking, and delivery - Alvin, Annie, and Vincent communicated well and answered the few questions that I had. I've only had a few short listening sessions with the 2 channel and the headphone setup, the improvement in sound over the Innuos internal DAC is clearly evident (as one would rationally assume.....not simply confirmation bias). The main improvement that stands out to me is that the edginess of the Innuos DAC is removed - the Pontus II provides more resolution, and a smoother response during my short A/B comparisons. My modest set ups:
2 channel - Innuos Zen Mini + LPSU - USB - Pontus II - Naim SuperNAIT 3 - Dynaudio Super Forty - REL 7Tx (pair)
headphone - Innuos Zen Mini + LPSU - USB - Pontus II - Eddie Current ZDS - Focal Utopia