I have a slow writing Sigma DP1, so the difference in write speeds to different cards wasn't really noticeable.
Recently I got a new 16gig Sandisk Ultra label as up to 30mb/s.
In the camera, the write speed is pretty similar to a old class4 Transcend 32gb card (15mb/s).
The surprising thing is that file copy from a card reader shows that the class4 transcend is faster, up to 15-16mb/s writes, for large 1gb+ video files, and around 7.5mb/s for the smaller photo raw files. The Sandisk Ultra barely breaks 7.5mb/s for large 1gb+ video files,and 6.5mb/s for raw photo writes.
The write speed is reported from win7 copying the same set of files from the notebook back on to the SD cards using the same card reader/writer.
Can anyone please report your 16gb Sandisk Ultra sdcard write speeds. Thanks.