I have used OO programming in Perl for real projects only relatively rarely, mainly for building modules, but I agree with the above, if the programs are simple, don't bother. But if you want to build a complex hierarchy of entities and behaviors, then it is a different story, OO programming really becomes handy. So, at the end of the day, it really depends on what you are doing with Perl.
And, frankly, I find the functional programming paradigm (à la Higher Order Perl) to be most of the time more efficient. But that only my own personal and limited opinion.