The upper mids/low treble on the HE-560 are very forward, that is what you are hearing. Some of us are very sensitive to spikes in that area and it can overpower the rest of the spectrums, as you describe. I ended up skipping this particular headphone for that reason.
Over time, I've discovered what I adore about the HD800 is the mids are actually laid back slightly, but the treble is forward. So it's oddly relaxing yet insanely detailed.