Admittedly, I only ever tested Sennheisers at the store and with friends, to see how they compare to the 7506; I don't own one myself. When connected to a top-of-the-line amplifier the HD-280 sounds slightly more accurate, but it's only really noticeable when playing something like a classical concerto, IIRC. I decided that they're not worth it, also because I don't feel like hooking up amplifiers to everything.