I've owned or used extensively just about all the contenders mentioned here - Sony 7506, Grado SR80, Sennheiser HD280, and they all left me wanting more. Since getting my Ultrasone HFI-780s, I no longer feel the need to keep searching. Closed back phones that sound open, image more like speakers, and easy to drive. Been curious about the ATs but until trying the Ultrasones I'd never come across a pair of closed back phones I could live with long term.