My findings are a bit different, though I have the added variables of using Cute's DYI Cable and now the Draug 2, both of which extend and tighten the bass considerably. I don't want to get back into the Sound Science Debate, it is in my experience, IMO only. The combination of the grill mod and this cabling opens up the soundstage, without affecting tone or bass (Conquistador you are using the Production Pads as well, aren't you?). It takes a great HP and makes it exceptional, IMO, I am looking forward to comparing mine to the HE6 and HD800's in Nashville!
Can you elaborate about the sonic differences you perceive with the Draug 2? Would you say the difference is of a greater or lesser magnitude than that introduced by the grill mod?