At home I use Q701's at my computer (running to a Xonar STX). I'd like to get a set of portable headphones or IEMs for work that have a similar sound. I work in an office with low cube walls, so full headphones are out because I don't want to appear "unapproachable". I'm not looking for sound isolation, since I want to be able hear if someone comes up and starts talking to me, but at the same time I don't want too much sound leakage since the cube walls are low. I'd keep the volume fairly low though.
My budget is ~$300 (maybe a bit more as long as it's worth it). I'd be connecting the headphones to my iPhone, and am okay getting an amp as long as it would stay within budget. I listen mostly to melodic dubstep and classical at work (not much vocal). Not a basshead -- the Q701's bass is about right. Good extension for melodies, but not fatiguing.