I run FreeBSD whenever possible, and I can say that I have had mixed results with CPAN. I go with CPAN first, but if that doesn't work, I go for ports.

There is no difference (b/w the same version) of a module installed via CPAN or ports, but the ports version is set up to install on a FreeBSD system. Beware, though, it uses whatever the system Perl is at the moment.

Back when I was a FreeBSD n00b, I always upgraded to the latest Perl from ports, but would forget to run the "use.perl port" command to tell the system that the new Perl is now located in /usr/local; if you don't do this, you will encounter strange issues.

So: try 1) CPAN, 2) ports, and 3) manual install as a last ditch effort