I just picked up a Vive Pro, so it might be a newer revision. I can tell you that when the sound driver actually works, the headphones are unquestionably of superior quality to the DAS, and similar max volume levels, so it is not a hardware problem (at least for my revision). I am an audiophile and sound engineer, and I own $5,000+ headphone/amp combos, so I understand good sound. The dynamic range is much wider on these headphones than the DAS, and the bass goes much deeper and cleaner (which can be enjoyed assuming proper positioning of the ear cups).
That being said, the drivers and/or DAC are absolute garbage on the Pro, and I have problems at least 50% of the time with the bitrate dropping dramatically (what people refer to as "crackling"), and sometimes the audio driver just cutting out completely and switching to a different device altogether, requiring a restart.
