Excerpt: From experience I can tell you that only the Extreme will work with the Hero 3 Black that I have. GoPro even told me I would not be able to connect with wi-fi unless it was an Extreme--not an Extreme Plus and certainly not the SanDisk Ultra. The speeds have to be just right. I am not sure GoPro knows why only the Extreme and not the Extreme Plus will work. I can understand why the Ultra class SanDisk memory card might not work--it is slow and meant for consumers.