Current couples performing the quad twist:
- Wenjing Sui/Cong Han
- Peng Zheng/Hao Zhang
- Julia Antipova/Nodari Maisuradze
They all managede to execute one (level 2) at Worlds '14, and they all have succesfully performed the move several times.
forgotten:
scimeca/knierim
I think we will see a lot more 4Tw on the way to OS 2018:
Duhamel/Radford ?
Savchenko/Massot ?
Volosozhar/Trankov ?