Plugged the Dragonfly in an hour ago. On the PC, it loaded software and the color just lit up.
I'm old. My ears are not what they were when I last sat and listened. I can't give specs. Just I hear big color.
I hear less difference on my phone, I expect a driver thing, the raw S9 Note 3.5 jack sounds better than plugging in the Dragonfly.
I think it would be easy to tell* what my same headphones were plugged into of the 5 options so far. The Dragonfly is best listening on the laptop.
Clearly there is a difference in [some] DAC/s Sure, like wine (something else I do) when getting to a certain point it is very hard to tell the difference.
*Last night I found the link to
https://www.audiocheck.net/ and gave Dr Pigeon the donation to test myself. Some of the stuff was pretty depressing - like Hi Freq range. Other tests confirmed I can hear stuff. That said, I sure think that was an easy $200 good decision.