
A900 has quite recessed mids, I've enjoyed my pair for quite a while until I heard AKG-K271S, they just trumped them but probably won't work in your case as need hefty amplification to sound their best.
ESW9 strikes a nice balance between being portable and delivering good sound, have groovy and fun sound signature too, could be bass heavy and thumpy out of the box, require some headband stretching to tame lows down a bit and bring out mids details. I liked them better than D2000 too. Have you considered IEM, I can wholeheartedly recommend Ety ER-4S, not all portables can properly drive them, seems to work fine with Sony X-Walkman, with Zune even maxed out they might not be loud enough.
Looks like im going to back away from the a900s because of the mids. Have you heard the ESW9? Hows it compare in all aspects to the a900?













