Looks good, works well... until it goes to sleep, and then it will refuse to wake up. It locks up the entire computer (Mac Mini) until I manually power off/power on the drive unit. This happens every day and makes the drive virtually unusable. I tried adjusting the power saving feature to both extremes to no effect. The discussion boards explain the power supply as the problem, particularly when powering the larger (1 TB or greater) drives and that is indeed what I'm using. Hopefully tech support will send me a higher capacity power supply but even if they do, this type of problem should never have been an issue to begin with.Update: Macally sent me an upgraded power supply. The problem has lessened, but still happens about once every 3 days (instead of everyday). I gave up on it. But I do give Macally some credit for sending the power supply; too bad it was not enough.