I've had the "California" switch, as Volks Caf� called it in the 90's, for
about 15 years.  It was not a whole lotta difference. The big difference, as
others have posted, was that new radiator I put in a few years ago.  I can
sit idle in 100 degree heat forever and not worry about overheating.  In the
old days I'd be putting the heat on to cool the engine down.  It did not
"cool" the wife off though.   :)

Bryan