No problem. The Nighthawk is by no means a bad headphone, it's just that in my opinion, from what I can hear, it doesn't come close to the P9.
I've had no problem with comfort of the P9's earpads so far, I find them very comfortable, but after a few hours the headband can start to hurt the top of my head a little. That's the only negative thing I can say about the P9. I'm willing to put up with it though because of how highly I rate the sound of this headphone.
I have the AudioQuest Dragonfly Red I use with my computer and have tried the P9 with it, I think the P9 sounds exceptionally clear, detailed and extremely accurate with it, but i've recently been using a small usb powered amp called the Focusrite Scarlett Solo 2 which also doubles as an input source for microphones and guitars/digital piano's, it's around the same price as the Dragonfly and sounds pretty decent too. I really don't think the P9 needs an amp with lots of power to sound it's best, because it's only 22 ohm's, but I do plan on buying one soon, just in case.