Pros: Impressive sound in technical terms (if that makes sense)
Cons: "Wrong" sound of the box (needs EQ)
I prefer the GR04 to my Visang GR02 and greatly prefer them to my Soundmagic PL50 (I don't like the PL50).
This review is not going to get technical. The main purpose is to share my EQ settings which makes them sound more like my HD600 which is my reference headphone.
In short: Great SQ for the money if you take 30minutes to EQ them.
EQ settings: (from PlayerPro on Android OS).