The HE-500 was originally tuned with velours, and the sonic signature remains the same. The original velours were more squishy and of course the original canare cable was a garden hose. The pleather option came about later because people were bugging Fang about it. They wanted the earpads to match the leather headband so Fang spent a bunch of time making them and revising them again and again.
Anyway I guess my point is that the current velour version actually is a much closer to how the original HE-500 sounded. The pleather version is just terrible IMO, i
t makes the HE-500 try to sound like the LCD-2, but a much worse version of it, congested with bloated bass. I also think it has worse timbre.