Sorry about resurrecting an old post, but there isn't much information out there about the HD570 because it was discontinued back in 1999. I remember, because I bought the last pair that was used as a display model from Circuit City (remember them?) on the way to college. List price was $150, I paid $110 I think. Best money ever spent, as I hated my roommates for the next 2 years and these headphones really saved me.
And when I finally discovered trance with Hybrid - Finished Symphony, I put that song on repeat for 8 hours and laid on my bed, searching for every nuance of the song and feeling like there was so much more to discover. I have such fond memories with my pair of HD570, when the earpads disintegrated I couldn't bear throwing them away. Ebay now sells replacement earpads for $8, which come with double sided tape. For $8, I will always keep replacing them until the speakers finally give out.
I'm not sure if it's the nostalgia, but I still love the sound characteristics of the HD570. I have a HD598 as well, which is considered better in every aspect. But for some reason, when I listen to progressive trance or classical, I prefer the HD570. It feels open and almost cold-like, but it's like 'm sitting in the middle of a concert hall, and I can almost look at the 1st chair violinist doing the solo, then look over at the cello section and just imagine their hands moving so quickly. I don't get that image with the HD598, which has a much warmer sound, and does pretty much everything else better - gaming, rock, anything with a bass, movies, etc.
I see headphones as something like Scotch. Every single malt has its own characteristic,and different people prefer different tastes. The HD570 may not have the best reviews online or a big fan base, but it's done more for my listening enjoyment and quality of life that no other headphone will ever come close. And its unique characteristics will likely never be duplicated again.
Other pairs I've used - HD428, Beats Mixr, M30x
edit: The HD570's full model name is HD570 Symphony. Probably gives a clue to its intended use