The original sv021 earpads have a problem with dissolving glue from skin oils, they fall apart (in my case) after 4-6 month. I have replaced many sv021 pairs.
What i did was remove and cleaned the plastic "twist-lock" frame from the originals, i used good thin strong double sided (tesa 4965 12mm) tape, cut small strips to the og frame cut away any access tape that was sticking out and mounted them to the Brainwavz Momentum 3 pad-frame. (Option: Glue)
Sounds very good to me, soft nice comfort, my ears (medium) fit in them,
Lets see how they holding up in the long run.