What I've learned is that with most tracks from this genre (rock, pop, 80s synthpop, gospel, classical) the DT880s are more than worthy in the presence of the Alpha Dog if not equal. It's just when I play music like DnB, hip-hop, EDM, dubstep, reggae, and anything that needs a serious kick in the bass department the DT880 becomes noticeably sluggish by comparison. The DT880 still has great extension and texture it just lacks impact and control that planars in general deliver.
i read swspiers review of he-400i and saw your comment on it. Are you still looking for he-400i?
i'm alright with selling mine and I bear the international shipping cost (since i'm in asia), if you're interested. Though tbh, razordogaudio has good open-box deals every time i open their website so, almost every week? lol.
The clamp force is a beotch though. and i'm not saying that just so i can curse, it really is.