i feel the HE-500's do have a bit of a cavernous sound to them that can make some recordings sound a bit weird and unnatural at times, but the HE-500 are still better than the 600/650 for just about everything. though the hd 650s/600s scale very nicely and are a steal at their low price.
you're right about the HE-500 and electronic music, best headphones i've heard besides the pro 900 and LCD-2 for it. theres just so much air in the music, and the bass, its perfect for trance, house, dubstep, drum and bass, electro, techno, and just about everything else. vocals are especially nice.
I disagree with you (obviously ), but I suppose it depends on what you want from your listening experience.
I've mentioned this several times--it's the reason I sold them. To me they tended to make everything sound like it was recorded in a cave; there's definitely a resonance there somewhere. I don't want to overstate it, but it's there. I spent a lot of time comparing the HE500 to the DT880 Pro and whatever else the HE500 brought to the table (and we all know its many virtues by now) the DT880 was definitely the more open, neutral and balanced headphone to my ears. Call me tin-eared if you like, but I just found that whenever I sat down to listen to music, I just naturally reached for the DT880 as the friendlier, more inviting sound.
Ditto. The DT880 was my first real full-sized. Though the mids are more recessed, I find the DT880 to have more dimensionality to the sound.