I bought this card for my Canon HF-S11 camcorder Canon VIXIA HF S11 HD Dual Flash Memory Camcorder with 10x Optical Zoom - 2009 MODELwhich specifies Class 4 or 6 memory because it records 24mb per second. I read that using class 10 may not work right even though its newer, so I bought the class 6 and it worked great. I've recorded to this card and extracted the HD video via Final Cut Pro and 8mp photos directly from Finder without a glitch just as I do for its built in memory. It came quickly from this merchant helping me meet my production deadline. Good experience all the way.
The write speed could probably be a little better, but it's not unbearably slow. I've read a few of the negative reviews and haven't experienced any problems with breakage, fragility, or failure. Granted, I haven't dropped it to the pavement or anything of the like, but I have frequently tossed it into my backpack and carried it around with the computer and even books without incident.
One complaint I do have is that my particular unit isn't exactly aligned quite right. I've got 2 USB ports on my laptop. When the flash drive is in the top USB port, it blocks access to the bottom one because it angles down. When in the bottom port, I need to make sure my laptop is not flush on a desk, as the flash drive will press against the desk/flat surface in such a way that I do believe will lead to breakage. As long as I take this alignment into consideration, there haven't been any problems.
