The pads from the SR-60s deffinately help the Grados. I use them on RS-2s. -- The HD600s are worth the difference over the HD580s IMO. The lack of resonance from the carbon makes a difference. The also have considerably more bass. You really have to want to listen to Grados to put up with the discomfort level. The Sennheiser is a good choice. You can check out frequency response curves at the Headroom website -- http://www.headphone.com/layout.php?topicID=10
