I bought about 16Gby Galaxy S3 already available and an additional 64Gb Micro SD XC Class 10.
As I have already ca 30Gby filled with memory and it runs smoothly.
Write values of about 10.7 MB / s
and reading values of about 19.8 MB / s
This recession only do so because had been asked in many forums also questioned whether the 64Gb Micro SD XC works at all is actually. (It works and no problems)
If now a lot of questions, why I have taken a card to 64GB, which is so together because my previous smartphone Galaxy S2 16Gb was very fast.
(Images or movies one makes you somewhere picks up live, large amount of data are just need the place also.)
========================= ======================== Update =
Use the 64GB for a week now
Was on a live concert because I once made an about 30 minute video recording with my Galaxy S3.
Result of video recording:
Duration: 27: 53min
File size: 3,34GB
Playing the recorded video works without problems.
(My first review)
MfG
Elmar =)