Just ran across this thread. Looking over the specs of the Pioneer I wonder if it's much better than my phone. In other words if anyone is truly interested in audiophile sound quality, it's worth taking a look at the LG V20 phone in addition to or instead of this Pioneer:

LG V20
ESS SABRE® ES9218 Quad DAC
http://www.esstech.com/index.php/en/news/newsroom/ess-technology-brings-advanced-audiophile-features-mobile-devices-first-time/

Pioneer
ESS SABRE® DAC ES9018K2M
http://www.esstech.com/index.php/en/products/sabre-digital-analog-converters/sabre-hifi-mobile-dacs/sabre-hifi-stereo-dacs/es9018k2m/

I also ran Rockbox on my iRiver H320, upgraded the hard drive from 20->40GB to use FLAC, modded the case, etc. It's the reason I ripped my entire 300 CD collection at least twice. At this point my phone makes it far more convenient than carrying around a second player.

As a side note, It's not great keeping headphones on all day, so I have close-range monitor speakers on my computer... definitely something you guys should do if you play music from your computer.