UltramabiI can't comment on the others, but I really like my Wicked Cushions pads for my M50x.
I have the non-angled synthetic leather ones. They're like pillows for your ears.
Sound wise, they reduced the bass a tiny amount, but cleaned up the quality and reduced the bloat. Worthy trade-off, imo.
My one complaint is that the fit to the ear cups is looser than I would like.
UltramabiI hope I'm not too late. I can only comment on the Sheepskin Elite pads from a previous Dekoni drop and the wicked cushions hybrid velours. I did not like the way the sound signature changed with the Dekoni pads. There was still a sound change with the wicked cushions but the highs were not overbearing (more than normal for m50x's).
birdlandBased on how they affect the perceived sound from my various Sivga headphones, the Brainwavz Micro Suede Pads will likely improve the M50's sub-bass extension and balance-out their mids and treble. The result: a less-forward, but more spacious and natural overall sound.
And with a larger interior space for your ears, comfort will be a vastly improved compared to using the M50's stock pads.
For more bass and less treble, choose Brainwavz' Sheepskin Leather Pads.