I have the HD800S and the elite sheep dekoni pads.
When I got the pads, I looked on here with regards to keeping the sennheiser dust protectors in or take them out whilst using the dekonis. Some discussion here said to leave them in when using the dekoni’s, so I left them in and What, the sound was muffled.
I went back to the stock ones and later decided to try the dekonis again, this time taking the sennheiser dust protectors out, once out it sounded great.
My advice would be to try it, I like the dekonis now, plus the dekonis have a built in dust protector.
Much much comfier with the dekoni pads, as for any changes in the sound stage, you have to judge that for yourself but if you try it, dont try it with the sennheiser dust protectors in also as its just one big muffle that way.
Just grabbed another penon official cable, these dudes are good at making nice cables that rival things that are hundreds of pounds more.
Really nice cables.