Headfier, Armaegis, has just published the newest review of Oppo's fantastic PM-3 headphone, with a heavy proviso:

“There’s something in the sound that bugs me. The sound is smooth and clean, but lacks clarity? no that’s the wrong word. Everything sounds... a bit wet. String and metallic percussive sounds lack shimmer and air (probably that treble dip). I guess I could say it sounds polite, but this changes when I use it on the go.

I really like it as a portable; seal and comfort improves a lot with slight movement and the PM-3 settles in without that puckering feeling. In this state the sound is really good. The midrange is still nice and clean, but bass has more energy, and that top end no longer has the wet feeling. Never discount the effects of physiology guys, especially with sealed headphones.”

Armaegis's PM-3 review is well-worth the read, especially as the PM-3's pads aren't easily user-replaceable, and may, or may not, fit your physiological needs.