So I got mine, and I want to post this in case they come up again and someone is looking for a review since they aren't on Amazon.
I got the case for the Samsung Galaxy S3. Overall its not bad, unfortunately no matter what I try I can't keep a micro usb cord plugged into the case when the phone is plugged in.
I've tried this with 5 different micro USB cords, including the one that came with my S3 and the only one that doesn't end up sliding out easily is the very short one (1.5ft) that came with the case. So it means I end up having to move that cord around or remove the device from the case and charge both separately.
Other then that it does a good job of extending the battery and doesn't add a tremendous amount of bulk to the phone. It won't be my standard case because of the charging issue but it'll be nice for travel.