Bought these ad900x for resell, cause it was impossible to get them in my country and prices for previous model was around 500$, but after listening them for a while I tempted to leave them for myself or buy 1000 model. So... the sound is great and clear, trebles are magical, mids are good and stright forward, soundstage is decent. Actually I'm even listening crystal method with them, bass is lacking thorough. Yeah, the only minus is the bass. Coming from m50 unamped with flat eq, bass is lacking indeed! It is present a little, quality is quite nice and detailed, but it's lacking the amount totally. The next step I tried foobar parametric eq and sony clearbass on walkman a864 with fiio e07k bass adjust and damn, they are very good eqing phones!!! Bass is very punchy and detailed, has enormous impact while retaining treble and middle crispness and quality in overall sounding. Now I'm thinking of ad1000x and bought momentum as closed ones Sources fiio e07k, sony a864 and fiio x3.

As for comfort:
They fit perfect for my mid sized head, I could spent a whole day listening them without any discomfort. The only issue is a plastic feel, not sure about durability. They are not portable though, so, it should not be a problem. Wing support is just perfect for me, they are not sliding down and clamping could not be felt at all.