After Firmware update version 1.3 for Panasonic Lumix S1 and S1R, now both cameras support CFexpress cards. Currently SanDisk Extreme PRO Type B CFexpress card now already in stock and shipping at Adorama.
L-Mount Rumors, Panasonic S1 & S1R & S1H Full Frame Mirrorless Cameras Rumors
After Firmware update version 1.3 for Panasonic Lumix S1 and S1R, now both cameras support CFexpress cards. Currently SanDisk Extreme PRO Type B CFexpress card now already in stock and shipping at Adorama.