I use the Sandisk CF Extreme 32GB card for several months now. There has been a single problem. For me, the map is a kind of portable hard disk for the most important data in the office. I synchronize with it between different computers (workstation, laptop, netbook) or just pop by. As a mobile hard drive for usual office applications of space far enough and the reading and writing performance is absolutely satisfactory. For larger photo sessions I use the card in my Canon 5D Mk II. Also, since it provides excellent services.