Apt update notifier - automatic package installation

Why doesn't anyone talk about the inbuilt apt update notifier? There is no end of scripts for downloading/notifying of package updates that duplicate update-notifier functionality. On feisty to get my apt package updates downloaded and installed automatically, I edited /etc/apt/apt.conf.d/10periodic to include:

APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Download-Upgradeable-Packages "1";
APT::Periodic::AutocleanInterval "0";
APT::Periodic::Unattended-Upgrade "1";

And then run apt-config dump to verify the results.

Update:
In Hardy, take a look at this file:

/etc/apt/apt.conf.d/50unattended-upgrades

I uncommented hardy-updates to allow those to be automatically applied as well. The unattended upgrade is performed by a python script:

/usr/bin/unattended-upgrade

which logs to

/var/log/unattended-upgrades/unattended-upgrades.log

You can run this script manually with -d to get it to write debug info to the log.