Hi, another endorsement for the Dekoni fenestrated sheepskin pads, from me.
I was somewhere between skeptical to cautiously optimistic going into it, but ended up liking them immediately. The way I would characterize it is that it makes the Susvara sound a half-step closer to the Abyss Phi TC:
Bass is more taught, and this is the highlight for me. Stand-up bass sounds in jazz recordings sound consistently more articulate and satisfying. I'm not sure I can discern less bass in quantity as some have mentioned, but the lift in quality is very nice.
Mids sound raised somewhere, which also ends up reminding me just a shade of the TC as well (I'm not really a huge fan of the TC's mids). I'd call it a minor step back compared to the stock pads in this regard. But also not worth dwelling on too much.
Treble loses just a shade of the sweetness that I've always loved about the Susvara. I'm not sure if measurements bear this out, but that's how I perceive it thus far.
What else? Imaging is a little different. Possibly a greater feeling/illusion of depth. The tighter bass might play a role here. I really like it.
And just generally, the pads makes the Susvara sound a little faster, and a small shade more aggressive.
The mere fact that a 3rd-party pair of alternative earpads don't make the headphone sound tonally weird is a minor triumph, to be honest.
So yea, most definitely worth a buy, even just as an experiment. Truth be told, you can spend Susvara kind of money on an alternative amp and not hear changes that are as interesting of a listen as this earpad swap.