I picked up these Dekoni pads and had a shoot out among these, the HM5 angled pleather, the HM5 angled sheepskin, the AQ NightHawk original pleather pads and the Alpha Dog angled lamb skin. I used the NightHawks initially for ease of mounting and comparing vs the HE-6 (my phones are modded to have a felt bass lens covering the full cup, with the pads stretched over the outside if the cups. I also have removed the fluff from behind the cups (but grills still on) and have performed the full blu-tak mod.
So, on the NH, the classic stock pads have the most bass, but that "muddy" and congested upper mid/lower treble many NH listeners have commented on) which is why I initially switched to the HM5 angled pleather and have been using most, and which I much preferred. Reduced bass (in a good way) and more transparent mids/treble. Then I tried the angled sheepskin HM5 and they were similar to the pleather, but a bit more polite at both ends. Slightly less energy at both ends.
The Dekoni on the NHs had more bass than any, except the stock, but it was more controlled. Also, the soundstage was more open had a bit more presence in the upper mids, without over emphasizing the treble.
So, onto the HE-6. Compared to the Alpha pads, which are angled and the Dekoni are not and not as thick, I get pretty much the same bass as the Alpha, and the same better presence, soundstage and upper extension I heard on the NHs. Alpha pads are clearly rolled off compared to these, which I don't feel I need with my HE-6 as they are. Bottom line, the Dekoni are the way to go for me, for now. If you have e HM5 angled pleather, they will be close, but a bit more aggressive and a different soundstage presentation, which I prefer less that that if the non-angled Dekoni.
YMMV. Happy listening!
Edit: corrected spelling of Dekoni in several places.