I use them both and am not planning to get rid of either, If I was strapped for cash and was forced to have only one, I might keep just the HD600 but it would be a painful parting. I really like the extended bass and the way the HE-500's hand percussion. But the HD600 is not a slouch there. The HD600 has a slightly better rendition of treble. Glad that I don't have to decide, Today I completed my role in a jury, good thing that neither headphone was on trial.