I have reviewed this product on an earlier version. It warned me of an imminent HD failure and allowed me (prior to Time machine), to make a backup and attend to the problem of the drive itself. I took my machine (a Powermac G4) to an Apple tech who confirmed the HD it was in a bad way. Apart from the enormous hassle involved when you loose everything - I had just transferred some radio interviews for editing. Disaster if I had lost them.

It's friendly green light gives considerable comfort, and if it detects an abnormality it can email you to warn you. Very important when you are away from your machine, as I am, for log periods. I have it running in one version or another, still on my G4 Powermac, and on my G4 Powerbook, and now on my iMac dual 3.06.

It is easy to install, has a check for update feature, and is reliable. Have had no problems with installation or upgrades.