Okay, after a long listening period, it seems like PGGB-RT (8fS, Extended, Speed) is performing very well on my system (JBL 305p mkii, IFI Zen V2) but there is something missing. I think it's "musicality". There is no doubt that PGGB has an analytical characteristic in its tune, but I think that's not enough. I can clearly hear HQPlayer delivering more "music" than PGGB. Rectify me if I'm wrong.
There is no right and wrong here, IMO. But there are a lot of variables to control for - with PGGB-RT, it is the noise shaping and mode. With my equipment (see below), I hear a large improvement from "maximize speed" to "maximize quality". If you're computer can't run "maximize quality" (this was totally me, until recently), using HQP can make sense.
How one uses HQP also matters - PCM vs. DSD, filters, dithering / noise shaping options.
Further, the synergy of your software with your DAC matters - some DACs respond to PCM better than DSD (e.g., Chord DACs). Other DACs is more of a toss-up (e.g., Holo). There's a lot of arguing about which DACs perform better with DSD (obviously Cayin RU7 benefits greatly from being fed DSD, others would argue that AKM and Burr Brown DACs do as well... no real consensus with ESS DACs).
Lastly, I'm finding RF / EMI "hygiene" matters a lot. I use a lot of Audiowise products, and employ batteries to isolate my power. I've also used low-noise, low-power network endpoints powered by low noise linear power supplies. I live in NYC and our AC power is quite dirty. The best way to assess the quality of your power is to see if you notice improvements in audio quality at night (when community AC power usage dips) vs. during the day. I've found I get a more consistent experience using batteries where I can.
How you upgrade / make improvements is also a guessing game unless one employs a highly systematic approach to system building, which can be costly in both time and money. I've found an easier way to start is to buy the best battery powered DAC / AMP you can afford that has a TOSLINK input as a starting point. For me, that was the Chord Mojo 2. It has excellent jitter rejection over all inputs, but has the benefit of galvanic isolation via TOSLINK so no EMI or RFI noise travels through from your computer to your DAC. Of course, you are limited on sample rate, but at least you have a strong idea of what your DAC / AMP sounds like from a baseline perspective with headphones. Then adding USB into the mix and upsampling, you'll gauge the differences - more RF and EMI noise seeps in, but your DAC gets fed with what is hopefully an improved stream of bits from your upsampler of choice. With your active monitors, you could also experiment by
powering them off of batteries / inverters.
In any case I hope my perspectives, based on my experience in my system, help you better contextualize your impressions. Again, there is no right and wrong - there are so many variables to control for that you have to maximize your musical enjoyment based on your system and constraints.