Just picked one of these up from eBay. Thanks for pointing these out and the details on how to format and use it on the A500 :)!
FYI - Just ran SD Card Tester on it and it ran at 5.91MB/s Write and 9.19MB/s Read. So inline with expectations for a class 6 card.
Samsung Galaxy S III (Android 4.3) - Duracell 16gb microSDHC
Sony Xperia Tablet Z (Android 4.3) - Kingston 64gb microSDXC Class 10
Sony NSZ-GS7 Google TV (Android 3.2) - 61" Samsung 1080P DLP TV