To people trying to upgrade to a 64gb Micro sdxc card: I had a lot of trouble transferring 25gb of data to the micro sdxc card and kept getting corrupt file errors. I found the solution by deleting most of my larger games and backing up the save data. Then I did the file transfer at about 3gb and never ran into the errors. You then have to redownload all your games from the eshop. Its successful so far, but for me it was very important to not have any transfer errors. Even if you “retry” a certain corrupt file and the transfer goes fine, I found it never quite worked right unless the transfer went completely smooth.