I also think something is fishy with the article on Headfonia. I have tried the pads from my k701 on the k501 and think that, although there are certain differences, the sound is not necessarily worse compared with the stock pads. I doubt that k601 pads could make such a "dramatic" difference,
I just recievied my 501's today and I want to replace the ear pads, but they are $30.00+ a piece. Are there different options or i'm stuck paying that much for them?