This is an interesting discussion, but one must bear in mind also that due to the two-tier nature of USB, much in USB sound quality depends as much on the DAC side implementation of USB as on the server/streamer side one, which would translate to certain systems needing as much of a USB "boost" -so to speak- as they can get to sound their best while others less so.
But while this is undoubtedly a real world necessity for some systems, it does not immediately make it a rule of thumb that can be applied in a more generalized manner.
So, from a methodological standpoint, the differences experienced in some systems would probably reveal more about these system's particular USB realities, unique for every system (a USB Achilles heel of sorts) than pertain to actual reference points relating to equipment properties.
Unfortunately, I cannot offer any comparative observations, since I have nothing to compare my Pulsar with at the moment, but the uplift in SQ is of such a nature, since it applies to a wider set of parameters than one would usually expect, that cannot be attributed to just one single aspect (e.g. Phoenix lite) and it'd rather point towards more elaborately calculated design goals (evolved mobo, ssd, power supply, layout, software, etc) that act in tandem to deliver this outstanding result.