I had need of decrypting Rijndael encrypted strings, monkeying about with the decrypted info, then encrypting the monkeyed with info. I'd struggled with a couple of other options before hitting CryptX. In about 5 minutes, I was on my way. The documentation and examples were clear enough for me to follow with little trouble.
I can't imagine trying to work with file systems without Path::Class. I often use the same scripts on both Windows and *nix machines, Path::Class keeps me from pulling (the rest of) my hair out. I find the documentation easy to understand, so it was quick for me to pick up and use with little trouble.
In response to Adina Adler - This module deals with an ordered list of things, so it's doing what it should (and does it quite well, I've previously used it). If you want to compare unordered things, I think you really want a module which deals with sets. I've used Set::Scalar to handled unordered things, with great success, maybe that'll get you what you need? If not Set::Scalar, then perhaps something else in the Set:: namespace?
I'm a hobbyist who only programs sporadically, but Moose makes OO programming a whole lot of fun. The documentation and examples have improved a lot since I first started playing around (back in the 0.2something-or-other days), which have helped considerably. Plus the developers are very responsive to questions, which is much appreciated when I start falling down a rabbit hole. If I could give Moose a higher rating, I certainly would. OO Perl would be a much sadder place without Moose.
I'm really enjoying using this module, much moreso than the older Tk set of modules. The only snag I had was my Mac (running OS X 10.5) had an older verion of Tcl/Tk (8.4), which caused some things to not work well. Once I upgraded (I used ActiveState's 8.5.4 distribution), I've not had any problems. Between the documentation with this distribution and the referenced Tk documention at tkdocs.com, I feel pretty confident.