How useful are header & body checks when used along side Amavis?

[John Allen]

My setup is Postfix (2.9.3) + Postgrey + Amavis-new + Dovecot(2.1.7) 
running on Debian(Wheezy)/Ubuntu(12.04) servers.
I have always assumed that header/body checks were worthwhile because 
they would catch some mal-mail early and thus reduce the overall cost of 
processing.
How useful are header & body checks when used along side Amavis? Are 
they still worthwhile?

JohnA
--
"Today's mighty Oak is yesterday's nut that held it's ground." - 
Margaret Bailey

Sent using Mozilla Thunderbird