I bought the fenastrated sheep skin pads for my HD800S despite all the warning over internet.
I must admit I love the build quality and feeling of lambskin on my face, however this earpad made my HD800S sounds horrible. Stage of the instrument is messed up. Bass is reduce. High is worse and details are gone. Overall, it made the sound of HD800S sounds like 100USD headphone.
I tried using it for a month and when I swaped the pad back, I feel like I got a new headphones.