No piercing treble? Punchiness that really pushes it? That's a problem with headphones like the HD800. Piercing treble when the track has punchiness, and that cannot be good for hearing, and it keeps you from raising the volume for the rest of the frequencies. I heard that 009 can be a bit thin sounding with treble emphasis. It's not fatiguing? With such descriptions I would have assumed it would be. When people speak of high-end highly resolving headphones they mean forward treble(boosted treble) to push details in your face, and for those tunes, they get fatiguing with various tracks.