I think perhaps I went a little overboard with my description of the highs as harsh, and stating unequivocally that they're not higher-resolving.
I really haven't listened to them nearly enough, to tell the truth. I guess what I mean is this: I would hear details I didn't notice with the HD 600 when listening with the DT880. Then, when I went back to listen with the HD 600, they were in fact there. The difference was that the more dominant treble brought them out more - which isn't necessarily a bad thing.
Now I want to go back and audition them some more. To be honest, they're growing on me - as did the T1 with more listening. In fact, I'd say that the DT880 are like a budget T1. They have a very similar character, with the T1 just a little better in every aspect. Conversely, the HD 800 is quite a different animal from the HD 600.
Given their price on Amazon in the US, it's hard for me to find a reason not to get them... Granted, I said that about the AKG K701 last week. Regardless, they're perhaps my number one "headphone of interest" right now.
I would not describe the T1s as similar t the DT880s. The DT880's have recessed mids and sizzly treble and are overall bright headphones. The T1s have forward lush mids with subdued treble and slightly warm. The tonal balance is quite different. Through in the improved bass depth and control and for me they are very different headphones. I did own both for 2 months at the same time before I jettisoned the DT880s. Sound stage wise, they are similar left to right, but back to front, the T1s do a much better job. Just my two cents from my personal experiences.
I figured someone would disagree with me.
Yes, the mids on the DT880 are somewhat recessed and the treble could be described as "sizzly". I find the T1 highs to be very similar (just with much better transient response), and the mids have more of an impact and a punch (sizzle, if you would like) - but I still found them to be a little subdued relative to the treble and bass. Not as much as the DT880 - perhaps even neutral, since I've been listening to my HD 600 a lot recently and that may have jaded my perception - but I still found them to be very similar. Soundstage-wise - yes, the T1 have far more depth and more precision (thanks to the faster transient response) - but the DT880 aren't bad.
One thing though - If I ever get the DT880, I want to replace the headband fork with those from the T1, if possible. That's quite possibly my favorite thing about them - precision cut aluminum.
I was listening to both on the Beyer A1 amp.