The problem with XML::Parser is not so much that it is hard to use, although it is quite convoluted in places. The problem is that SAX is a standard alternative to its streaming mode, and that XML::LibXML is a way better alternative to its tree mode. Plus XML::Parser is not actively maintained at the moment, which is always a problem when a new version of Perl, or of expat (the underlying library) comes out.

So if you need to work in stream mode, your time will be better spent learning SAX, and if you are looking for convenience then XML::Simple, XML::LibXML or XML::Twig (or any of a number of other modules) are certainly better choices.