Summary: I have bought 3 of these cards to use with my new Canon EOS 5D Mark II. In tests I have done they did keep up with the camera saving 17 images at the full 21 Megapixel RAW format in continuous shooting. They stand to what is advertised. I'd buy more when I can afford them.
Summary: I use this CF card with my Canon 5D-II camera. Since I usually take my photos in RAW format, I needed a large and fast medium to store those 24Meg+ images that the camera creates. The write speed is very fast, since the Canon takes advantage of the UDMA transfer speed -- I hardly notice the "activity light" on the camera -- it seems to write an image in less than 1 second.
Pros: Durable construction, Easy To Use, Large Capacity, Reliable Performance, Writes/Reads fast
Summary: I needed a faster card for the Canon 5D Mark II. All I need to say is, "this card was the perfect choice". I've used SanDisk cards for years, and have yet to have one fail. I'm still using cards that are 5+ years old.