Porpoisehork did you connect the drives via SATA to enabled TLER, or were you able to do it via SAS?
While you are doing TLER you should also do WDIDLE3 ... the western digital utility that lets you set the spindown timeout. The Load Cycle Count (number of times a hard disk is rated to park its heads) is usually around 300,000 for a standard desktop drive. I didn't enable it on my original WD15EARS array. I was poking around in HD Tune (Health tab when drive is plugged in individually) and noticed that in 5 months the drive was already through 60% of it's rated parks.
I've attached a zip of both utilites. It includes a virtual floppy disk image you can use to create a bootable floppy or CD-ROM.
Here are links about S.M.A.R.T. (Load Cycle Time), WDIDLE3 and WDTLER.