Perl's biggest strength is the CPAN. If you're thinking about opening a socket at all, you're probably missing something. If the socket endpoint is a webserver, look at WWW::Mechanize or LWP. If you're hoping to do SMTP, look at Net::SMTP or MIME::Lite.

That said, the choice between "by hand" and IO::Socket should be pretty clear, but between the CPAN and IO::Socket you should choose something from the CPAN.