Nikon MC-CF660G CFexpress Type B Memory Card

I have a Z9 and had the same question before I ordered this card. I pulled the trigger based on Matt Granger's tests, which showed this card as the rough equal of the Prograde Cobalt. That means that its sustained write speed will be similar. When my card arrives, I will test the buffer size at 20fps raw. I will be careful to ensure that things that affect the buffer (eg. Active D Lighting) are turned off. If I get 80 frames before the buffer fills, that will double confirm the sustained write speed. I will then select high continuous of 12-15 fps in raw and fill the card with a single burst. If the buffer remains unfilled (Thom's testing on other cards showed that it did not fill) then this card is triple confirmed as just as good as the Prograde Cobalt.