If I could wind back the clock, I would have rather bought a cheaper 1Gb (or 2Gb) card than this premium card which is no faster.
I did some tests on the 40x card versus the 80x card using a burst of 5 images in RAW format. The 80x card was nearly, but not quite, twice as fast. I'm thinking it was not exactly twice as fast because of limits maxed out on the camera as opposed to any issue with the card.
The card itself appears of good quality and to date has been reliable.
As yet have not made the time to test the software which comes shipped on the card itself (Image Rescue 2) although it installed on my machine running XP without issue.
Recommended if you need the speed.