Got a good chance to compare the HE560 to my own HD600 today. Level matched but on different amps.
I found that the HE560 still had a bit of that treble tizz that gets to me when listening at high levels. Not too different from what I remember the HE500 actually. In direct comparison, the HD600 had a much softer treble texture while maintaining equal (if not better/cleaner) attack. I would speculate that the HE560 does show to have a minor treble spike somewhere. Was ultimately hoping it might be more controlled and refined in the treble though.
Most of us agreed that the HE560 was superior at reproducing bass. On first listen, I actually didn't think it was significantly better. But part of it might be me preferring dynamic bass to ortho bass.
Regardless, I agree that the HE560 is an excellent headphone. Quite neutral and open-sounding which suits my two biggest priorities. But probably not good enough to pull me away from an eventual HD800 upgrade.
Did you just compare these two at the meet with regards to treble refinement? Or also against other well-known headphones? HD600's treble is relatively linear but with dips around the definition and sparkle regions, plus lack of decay issues leads to an aggressively smoothed treble.