Agreed, but the fact remains that the HE-400 does have a slightly bothersome treble. With jergpad and slight EQ it's perfectly fine.
Slightly unrelated story. Back when I owned my Fiio E17 and Senn IE80 I gave it to a friend to have a listen since he was curious how it sounded. I usually listen to around 30-35 on the 0db gain setting. Plenty loud for me. When he started listening he set the volume to 60 (max)! He even asked if it goes any louder but I refrained from telling him you can increase the gain for fear of his hearing. I was shocked.