I own a set of these and a set of HD600. They are two different headphones. If I had to pick one, just for audio quality, I would go with the HD600, or 650, but I prefer an open back headphone. There are a couple areas where these head phones have the HD600 beat. They isolate better, I believe they weigh a little less, they are easy to drive, and they are STURDY. They might be the most solid headphone that I have ever owned. I did end up switching out the pads. If you are looking for a decent headphone that you can carry around town without the worry of them breaking, these are for you. They sound good and they are duarable. I end up listening to them more than my Stax, Hifiman, or Sennheiser, because it is what I take out when I leave the house.