I've not extensively used it yet, but this module seems to offer a great visual improvement over the Data::Dumper output.
Also, the documentation is very complete and the examples are relevant.
Consider however that this module does not emit valid Perl code, so the return value can't be eval-ed to get back a copy of the original data structure. So it's aimed solely at debugging/visualization purposes.
The author seems to be extremely kind and responsive too: he corrected a (minor) glitch in Makefile.PL (in version 0.32) and posted a new version in just a couple of hours after the report.