Exporter::Proxy: Simplify service classes while you unclutter your namespace.
One obvious advantage to OOP is avoiding namespace clutter. Splitting up large classes can still require exporting symbols, and can still end up with namespace collisions on the exports.
E::P helps on both accounts with simple symbol export (via Symbol) and an option for adding a dispatcher to the included classes. The dispatch method looks like $thingy->yourname( op => args ) and simply strips off the op, and re-dispatching it via __PACKAGE__->can( $op ). The dispatcher provides a namespace for its op's, which can then be more mnemonic.