I just find them incredibly un-involving. I really thought about it, and it might be the lack of lower bass rumble and extension. The bass is tight, but the actual punch feels wimpy, like being hit with a marshmallow. My HD650's on the other hand grab my attention within seconds and keeps me focused on whatever is playing. Is the HD650 camp really that much farther into the dark side though?
Note: these are the 600 ohm version.