have you heard the headphone or just read a couple impressions? Most impressions are very positive. a few are not. measurements are mostly excellent, too, if that matters to you.
I've heard lots of headphones and the Momentum sound excellent. deep, textured bass and clean mids and treble with no harshness or glare.
anyway, here's a quick contribution to the thread. I don't own them anymore but the HP1000 are gorgeous, imo.