I have tried every conceivable pad, and some of the mods, and my overall opinion is still the same.
That is why I traded them.
It was either a slight peakiness around 4khz that bothered me or the slight lack in the top octave.
Frequency response graphs from various sources, and my own personal hearing backs up my findings.
Plus certain headphones such as Stax, certain Sennheisers, vintage Beyerdynamic DT990, and even the HE-6 simply have more top end extension past 10 k
Plus they arent as visceral and dynamic as some of the above mentioned cans.
Please dont get me wrong. The HE-560 are a excellent pair of headphones, and did some things exceptionally well, and I miss them sometimes, but their overall signature and slight weaknesses just didnt suit my tastes.
Not trying to start any arguments at all, just stating my own personal opinion.