"Swear by Sandisk"

The only company capable of making a reliable micro SD at 64 gigs. In all reality they are the only company capable of making a fully reliable SD card period, of any size and type. Despite the Galaxy phone issues, this card has excellent read spead, format speed, and decent write speed. I upgraded from my 32gig SanDisk (that I paid a mere 20 bucks for!) in my smart phone to this and had absolutely no issues.As a complete side note, I'm amazed at the capability to fit 64 gigs on a micro SD. I love it. My friend runs a tiny homemade built PC off of a 16 gig Sandisk as the harddrive and it works brilliantly.

"My galaxy s3 loves it!"

I bought this with the sole intention of putting it in my Samsung Galaxy S3. I had to use a tool to format the card to FAT32, but once I did so, the card worked great. I have been taking advantage of the extra room I have for music, videos, pictures, etc. The SD adapter that comes with this is also handy.The transfer speeds didn't feel like class 10 when connected and transferred files from my computer, but my computer is 5 years old, so it's very possible that it's the problem. Other than that, I'm completely satisfied.