[Discuss] How smart is SMART?

[sweetser at alum.mit.edu (Doug)]

Just lost a 500 GB 2.5 inch SATA drive made in Thailand from my Mac
Mini server.  A half hour to boot was the signal.  While I could have
set up RAID, all the data I care about is in a Dropbox folder, and I
have Time Machine to get at any apps.  My data is on three computers I
control, the drop box server, and Time Machine.  I spent $260 for a
$100 hard drive because I used Computer Loft to deal with my fear of
mac hardware (so many wires in such a small place).

The main costs were time and money to reset the box.  I have been able
to update some things, so the machine is a little more streamlined
now.

Thinking about the future, does anyone regularly monitor their hard
disk SMART (Self-Monitoring, Analysis, and Reporting Technology)
information?  I found a $40 utility that would do this work for me,
including running both short and long tests.  If it is wise, I might
do this once a month.
http://www.volitans-software.com/smart_utility.php

The long tests can last 3 hours.  One thing I noticed was the
replacement for the dead disk is running about 14 degrees F warmer
than the other disk (right now 48C versus 41C.   What temp is BAD?
Does anyone continuously check on that?).  That may be a lead reason
for it dying first.  The replacement might die before the cool one.
Now that the test is done, the hot disk is down to 38C.

Are there scripts anyone uses that go through the same data and/or run
the short and long tests?

...and a few moments of googling to
http://en.wikipedia.org/wiki/Comparison_of_S.M.A.R.T._tools says...

GSmartControl
smartmontool

Now my more targeted question: does any use these two programs and
would like to share their opinions?

Just trying to be a sometime responsible home system admin,
Doug