Eh, I'm not really interested in modded pads, as it happens. I even prefer the pleathers to the velours in just about every way, so I'm already something of an anomaly around these parts. I detect no difference most of the time. My ear pallet is probably not as trained, but I also don't desire it to be!
But I don't frown on pad modding or anything like that. I probably avoid it because I'm hopeless when it comes to doing anything with my hands.
lol... I like the pleathers as well more than the velours.... Try it... Just take the pads off, turn them inside out and cut some holes, then stick the pads to the frame with double sided tape. Does make them sound quite a lot better, HIFIMAN would probably have done it as well but it would make them more difficult to manufacture. Some headphones have those mods already, some Sennheiser and the Audeze have it already I think. It definately makes them sound better with the pleathers, I didn't bother with the vent part of the mods because I tried it and it made the bass worse.