I really don't like giving negative reviews but think it's justified in this case. I bought this card last month (Nov '11) and used it on a commercial studio shoot the following week. Out of approx. 300 images shot, 3 were unreadable on importing to Lightroom. This was enough to make me nervous because I can't afford to loose clients images. Not because of the hassle of retaking, but because my clients tend to be on tight magazine deadlines and simply don't have time to reshoot - even at my expense. However, I gave the card a fresh format and another chance. A location shoot in Wales went well (5D mk2). It was a personal stock project so I thought I'd take the chance. All the images were fine. So, earlier this week, I tried to use it on a dance performance shoot for a client - the card failed straight away. My camera (1D mk3) reported a card error and I'm not prepared to attempt using it again. Two failures is enough for me to switch straight back to Sandisk which I've always used in the past with zero problems.
I'm not sure if this review is helpful or not but it's an honest view. Maybe I just got a bad card. I've got three 16GB Transcend cards which are fine. But this experience is enough to persuade me to spend the extra and switch back to Sandisk in future.