I concur with earlier replies that OO is preferred when you (i) anticipate your code with be reused, (ii) when the code will be used as part of a team development effort, or (iii) distributed in module form.
It is also worth mentioning that, it is a good skill set to acquire if only to improve your familiarity with and ease of use of techniques used by CPAN modules. For many (if not most) Perl programmers, the ability to make ready use of the CPAN is half their value as a Perl programmer.
In general, I think everyone who uses Perl more than casually should take the time to create a module, if only a "Hello World", for the valuable experience it provides.
