Using with Canon 60D for over a month. Works without any issues (as one would expect). Wonder though if I really need this kind of performance, but helps with copying photos from camera to PC (get about 20MB/s copying speed). Camera easily can store over 1500 pics (difficult to see exactly how many, as display counter only goes up to 999) on this card, and video recording works without glitches (have not recorded long clips though, typically around 40 secs max). Will be testing cheaper cards soon (got a transcend 32GB, class 10 for around $50) to see if the premium for this card is worth it. Sandisk though seems to have no problems with their cards, and I do not want to loose any photos!!!