I just got mine yesterday, how long do they take to break in. They sound great out of the computer, but even better out of my Eximus DP1. Very well balanced, detailed. Being a noob I was wearing them backwards for a bit heh.. but they were still comfy. Anyways I was one of the people who thought they were butt ugly, but they aren't that bad in person. They seem really well built too.
I like the open sound, its very natural. I guess with a closed headphone you get more bass. The 598s have bass, seems very accurate, but most people like that saturated bass.
The headphones aren't as good as my regular stereo though, but still very nice. The headphone presentation is so different its really hard to make that comparison I guess.
Detail is great.. on the Eximus you only need to turn it to 9, whereas the Beyer T1 needs to go past 12 (I don't own the T1, just listened to on DP1.)