I've been thoroughly impressed and pleased with the HE-400, but I'm not the only one.
I work at an audio/video production studio and there are DT-770 PROs provided for everyone, so I brought these in just to mix things up. As a woman from Finland I work with walked by, she could easily hear the music through the open grills and thought I listened to it too loudly. I gave them to her to see it wasn't loud. "You are right," she said, and went to hand them back. "Oh wait," she took the headphones again and listened for a minute. "Das high quality sound!"
Who am I to disagree?