I've heard that they have a more forward sound than the HD600/650s. Do they have any similarities to the HD600/650s? Or are they completely different? How about the bass? Do they not have a lot of bass impact? Is the forward nature of them mainly in the high frequencies?
I went straight from a 600 to a 595 and consider the latter vastly superior in all areas but especially openness; the 600 sounds very cavernous and shut in to me by comparison (I think someone else said the same here when comparing a 595 and 580). This is using a Marantz integrated amp; results might be different for those with dedicated HP amps but I have no interest in such devices. As for forward, the 595 has a much better defined treble but I wouldn't call the sound forward in any way, just natural. Indeed it's a long time since I've been less conscious of a headphone's traits and more concentrated on the music--thank you Sennheiser. Now if you can just address that little matter of slightly creaky joints (a little like my own in fact) and microphony we'd all be in seventh heaven.