As a Mac support person, I have found SMART Utility invaluable to give me advance warning of drive failure. I used to have to run TechTool Pro's Surface Scan to confirm bad blocks on a drive; or, on some drive models, Disk Warrior's entries in the System Log reveal replaced blocks. Either way, it took a lot of disk activity on a possibly-failing drive that could prevent timely data salvage. SU will tell you immediately if any blocks (sectors) have been replaced, which is almost always a sign of a failing drive. I deal with several failed drives per week, and at least half of them are due to bad blocks. SU's other attribute reports will also warn of impending failure due to other causes.

Note that Disk Utility's Smart Status will typically only tell you a drive is failing after it's already gone belly-up. Thank you, Doctor, I could have figured out for myself that the patient had expired.

Some feedback posts have complained that SU is just a GUI for smartmontools. While it is that, it is more also. First, for those of us who don't know how to make smartmontools work, there's nothing wrong with a GUI; those of you who want to remain pure and unsullied by GUIs can do so. Second, SU doesn't just report attribute failures, but has an algorithm that gives you advance warning ("Failing") and the red "Failed" alert, so you don't have to be intimately familiar with SMART attributes and which ones are important and what values are normal and abnormal.

SMART reporting does not work over most Firewire and USB connections. That's not the fault of the software, it's a function of the external enclosure.

The only features I would like to see added are email notification and a menubar icon. I have suggested this to the author, who is very responsive to questions.