Just thought I'd chime in as someone who owns this DAC, I use it with the onboard headphone amp to listen to 320khz and HD streaming and it sounds beautiful (especially the latter) through my cheap AKG K-92's.
This setup replaced my vinyl rig - Revolver turntable with Moth tonearm, Audio Technica ATF3 occ cartridge, Arcam Delta 290 amp with optional phono stage and Mission M71i speakers and stands.
Although I preferred the sound of my vinyl rig (I prefer speakers always) the sound quality is very, very similar with the headphone setup extending into the sub bass further.
Testing sound quality has to involve the ears.
I think it is good with someone that says their opinion. Would be interesting if you also tested another dac hat.... it is so hard to listen to the difference otherwise when you have n=1 observation