I liked the HD 58X better than my HE4XX from the moment I put them on. Today I added a C3 Audio UPOCC balanced cable. I am listening to Prokofiev's Romeo & Juliet from a hi-res recording thru a Fiio X7mkII music player and the sound is incredible. I'm not a good critic but having sung with the St. Louis Symphony Chorus for a couple of seasons, I feel like I'm on stage with the orchestra.
javacupperI actually feel the same way about the 4XX, like they're still fantastic headphone and I can't complain about owning Planars for the price, but these really just sound so fantastic... I just love listening to music on them. Granted I'm waiting for the 6XX's to do some A/B'ing, but darnit if these aren't the best headphones I currently own.