proedros
Headphoneus Supremus
It is fairly simple, these 2 are distinctively different but yet if you can answer the questions
Do you want to hear the emotions and expressions of your music ? Or do you want details and clarity that you can pick a part ?
The answer would point you to Zx2 or DP-X1 accordingly. That is sound quality wise, power wise, Onkyo has the obvious upper hand
you shuld post the IQ/EQ ratings and what these mean - it would be helpful to people here i think