Have you ever listened to Akg K550? I got one recently and I think it is very good for a closed pair of headphones.
Though it does some things better than HD650, I still consider HD650 to be better, but they are perfect for office and noisy environments.
Some people say it is better than AKG K701 ( I liked it more too, though I did not have much time to compare them ). I sure consider them to be better than DT770 :D