I only listened for a few minutes but I brought my JH13s along to get a good take. I preferred the 901, sound and UI. The UI was genuinely good. That said, the Studio continues to surprise for what it is and costs. The Studio has a tangibility to it that's unique but the 901 has an extremely refined character to it. The amount of unenhanced res and texture (admittedly HiDef) was impressive. I though it could have had a bit more PRaT but honestly, with IEMs, a bit relaxed is generally better than a bit too aggressive. It also didn't seem to have any impedance induced niggles. Again, I don't mind commenting but I will defer to Jamato as my listen was very uncontrolled and short.
Edited by goodvibes - 3/24/13 at 4:07am