For testing, I have the card with video files (50 - 500MB per file) fully written and am going on around 50-58 MB / s / come when writing and up to 95 MB s when reading. Thus the card is significantly faster than specified. According to the manufacturer 60 MB / s read and 45MB / s write.
Works in Nikon D800 and Canon 400D, we but in a Nikon D300 as "card full" and reported (after formatting in the camera) can not be used in the D300!