To my ears, velour pads smoothen the treble slightly but with the result of having them lose energy as well. I prefer to decrease the treble of 1-2 dB's when a record calls for it using my analogue tone control and stock pads, but that's personal taste. Surely, treble is the region where swapping pads has the least negative trade-off.IF the velours make them sound significantly brighter in the upper treble and lose a significant amount of the sub bass (also if they made the quality of the bass worse), then I could probably say that I would not like them, IF they only lose a very tiny amount of sub bass, do not significantly increase upper treble (above ~10Khz), that could be good.
Bass is a different story. It is is more present with velour pads but quality decreases as it gets much looser, defeating the purpose of having planar phones imo. Again, a couple of dBs added there and problem solved.
What I'm trying to say is that if your LCD2Cs need adjustments, you would achieve better results using a tone control for fine tuning rather than changing pads, for with the former you can change quantity without compromising on quality.
I'm back to the stock pads and I'm enjoying them more than ever. Also I feel that the seal is much less noticeable than it was when they were brand new. I don't know if others can confirm this but it doesn't bother me anymore.