What benefits does this give over just installing thru the CPAN shell?

Debian's package management system is, in a word, beautiful. I have a cron job run every night to pull over the list of the latest packages. Then, when I want to make sure that my system is up to date, I run 'apt-get upgrade', and all packages that have a newer version out there get upgraded. I'm not sure that I'd want this in an enterprise environment, but for me personally, it's a Good Thing. Also, with apt, you can have programs that use perl modules have apt dependencies for them.