I must be lucky,
I have never had a hard drive fail at all and I have had around 20 of them mainly Seagate.
Cooling does make a difference...I have always purchased Antec case's that have a lot internal cooling.
Regarding cooling your better off having front and rear fans supplying air flow in 1 direction then having fans on the side of your case that actualy decreases and disrupts air flow.
Glad to see it's working for you Al.
http://www.antec.com/Detail.bok?no=390