Michael J. Eckman "Mike"
I bought this as supplemental storage on my Asus Transformer TF201 tablet.  The card did not need any special formatting to work and just worked upon first installation. It stays plugged into my tablet non-stop and I've been using it for about 3 months for additional storage for music and videos without any problems.  I don't have any speed benchmarks, but I haven't noticed any slowness in copying or deleting large amounts of data on this device.  It does what it's supposed to, so therefore, I give it 5 stars!