I don't know the 250 Ohm version of the DT 250, only the 80 Ohm version. There is some evidence that the 250 Ohm DT 250s are better. To some extent, what has kept me from ordering the DT 250-250 blindly has been this graph. This curve looks just a bit nasty where one would want it least, I guess: no matter which channel is the one measured accurately, there is a 5dB difference smack in the mids, between 200 Hz and 1kHz. This is similar to the slight coloration that I have always felt I perceive with the DT 250-80s. Overall, it's very enjoyable, but it sounds just a little bit boxy and closed, and I have been afraid this might be caused by resonance from the enclosure, which is
quite small and closed.
But, Xander, I am a little hesitant to recommend trying the bigger 770 or 990 Pros yet again. I am somewhat afraid of your audiological verdict.
Edit: acidtripwow, I have just seen your post. This is great: another DT 770 vs. DT 250-250 shoot-out. lini ended up liking the the DT 250-250 more. I am very curious what you'll report!