Simple, easy to install and use, and with decent documentation. The only drawback is the inconsistent value for unknown/undefined values.
Sometimes unknown values are undef/empty string, whereas sometimes, an unknown value is returned as an empty hash. This makes it slightly more fiddly than necessary to use. It would be easier if they were all undef.
Might be nice to document what is returned, though, admittedly, a quick Dumper is not too much trouble.