I'm sure it's been brought up in here already ,( didn't read the whole thread ) but having the Superlux 662, basically the same shell/pad size, I use the Creative World of Warcraft Soundblaster headset pads and it's a world of difference ( ouch I didn't mean that lame pun but it happened )
Should be able to find them somewhere, very soft.*** But that's pleather, not yet found anything worthy in the velour. The Samson are semi-open (if I recall correctly ) so the pleather will keep your bass levels and the staging should stay more or less the way it is stock , velour should drop the bass levels off a bit and possibly give a bit more of an open sound.
I'm sure I just told you what you already know though.
That might be good because the Samson feels a LOT like a closed phone for an open phone.