On another note, do you know if the sandisc extremeiii 4gig cf card will work with the zd? Or any other 4gig card for that matter?
I bought an A-data myflash card 4gb on ebay 100$, they claim to be 150x, they are fine to shoot but the Mamiya gives a problem to format it. I still have to fully test it, I don't know about the extreme III. I think that all 4gb sd cards are made with the same samsung chip, despite the ugly rose label A-data ones they have on.
As for velocity test, I can only compare it to my 1gb sandisk ultra II; in camera writing is the same more or less, reading is a little more fast (an image is displayed on screen about a sec before the sandisk). Copying to the computer is another history, example: copying 4 files (36mbx4) takes 22 sec with sandisk and 6 sec with the sd, about 3-4x times faster, the differenci is obious. I have used the same card reader with both +but here we would enter in card reader differences
Another note is that mamiya formats its cards with Fat, and it reads Fat32 but depending on the program you have used. As an example it doesn't recognize Windows OS format but it does with Lexar Image Rescue...don't ask me why, they both are Fat32.