On the pro side, it's quite easy to use and straightforward.
On the con side:
* There's no documentation about what happens if a parsing error occurs.
* In fact, if an error occurs, an unhelpful message is returned - "syntax error (word) at 199". It would be nice if the module could count lines, and if its error messages were a bit more descriptive.
* Along those lines, it would be nice if the module had a routine for parsing a file containing JSON.
* The bare keywords feature is nice (for data that's only supposed to be used by this module), but turning it on is awkward - I'd rather it be an instance variable than a module-level variable.