My latest acquisition in the headpone arena, perhaps one of my best! Got them 2 days ago (after selling my AKG K271 and Sennheiser HD280 headphones), and I have to say these are easily my favorite closed headphones, surpassing even the K271's (which I liked quite a bit, but in the end were just a touch bass shy for my preferences). Anyway, the DT250's match the K271's in overall smoothness, but have a bit more relaxed sound, just a little bit more laid back w/detail presentation (which I like), and signifigantly more bass power. Add to the fact that they are smaller, lighter, and more comfortable (velour earpads - yummy!), and you've got a real winner.
After the last "head-fi" meet at my house, I didn't think I'd ever find a closed headphone I could live with (I only really liked the "open" headphones that were there), but a quick trip to head-fi.org helped me quickly narrow down my potential choices down to the DT250 or the Ultrasone HFI-650. Since the 650 is generally considered to be a touch analytical (and can only be ordered from a dealer that does not offer a trial period), and the DT250's were described as very balanced (and can be had from headphones.com w/a 30 day trial period), it was really a no brainer choice.
After a bit of break in, the dynamics on these things is pretty impressive. Listening to Nine Inch Nails and several times hard transients from soft to loud have actually startled me. Nice! They are more amp dependent than my Sennheiser HD600's. The 600's sound good on both the Xin super mini (with battery boost) and the Xin supermicro. The 250's only sound good on the supermini w/battery boost (smoother).
The funny thing is that I keep forgetting which ones I have on at a given time. The DT250's and HD600's don't sound exactly alike (the 600's are more laid back and not as dynamic, but also don't have that slight shoutiness and they seperate instruments a bit better), but they both just let the music flow. Nice.