Nice choice Stan. I owned the HE500 at the same time as the hd650. The 650 was sold a week later... It was the more focused imaging and clearer- smoother sound that beat them for me. Plus they have one of the best treble out there ime. I much preferred them with the velour pads over the pleather as this made them a little more airy.
I've never compared them against the hd600 side by side, so I'd be interested in your opinion.
I picked the HD600 over the HD650's when I compared them based upon the HD650's slightly toned down treble. That's why I'm expecting the HE-500's to put a big smile on my face, especially with the Mag Planer quality bass blast. I'll be sure to post my feeling once I've given everything a fair listening to. That damned truck better get here soon before I burst an artery in my head waiting for it.