The worst thing there is. The first one I bought crashed during the transfer of a large volume of data (around 35gb). It copied quickly up to a point, then it froze and... that was it! From then on, it took around 4 minutes to copy just a few mb. I returned it to the store and they kindly gave me another one. As soon as I tried to transfer 8gb, the exact same thing happened. It crashed and stopped copying at 6.9gb. Now it takes 23 hours to transfer 312mb!!! Needless to say, I formatted it, but nothing changed. If I could, I would give it negative stars!