I'd love to hear your long term thoughts on these two headphones. After auditioning the PM-3, my thoughts seem to parallel yours. I think I'm someone who loves treble sparkle, and I've been looking for a closed back headphone with a neutral sound signature. The H6 was the only other headphone that seemed to meet that criteria within that price range. I've heard the H6 has a larger soundstage... But I wonder how good the detail and bass are in comparison... Along with that treble sparkle you mention.