I found classes very usefull. It allow to write object code in perl5 without having to do a lot of stupid controls that are not related to the code itself.
It allow to have very compact code, and really natural, from my point of view.
I am really astonished that "classes" seems to be not very popular. Perhaps it is because of Perl6, but there is a lot of Perl programmers that don't intend too use Perl6 in a short term. And "classes" seems to be a really good way to produce object programming in Perl5.
This module is one of the most usefull Perl module I know. The only drawback I found is that it is a little bit difficult to install. The problem come from some modules dependencies (I never remember which one, but the same compilation problem occur with active state perl (windows) and unix perl (debian)).