I bought three of these cards. One died one day (in my Galaxy S3) after about a month and a half of use. The phone said the card was removed unexpectedly, and it never functioned again. The phone still recognized all other cards. I contacted SanDisk, and they shipped out a replacement under warranty.The cards have served me well. Two are in Galaxy S3's, and another in a Galaxy Note II. Copying to them is decently fast, and they are great for music or video storage. Phones have no problem playing 720p video off the cards.