I use a canon T1i for timelapse and video, and really push rapid shooting. I have used it on a mountain in snow and moonlight at 14 degrees, and only once encountered a small buffer window on a long video take at 1080p. It works great, I have never had problems with Sandisk cards, they help me make a living at shooting. I also use Ultra II cards, and only notice the smallest of time difference writing to the card in camera. Loading to the computer data from the card does take longer then the ultra, but unless you need to dump data fast this one is fine and cost less. I would go for storage size over file transfer to computer speeds anytime.