One of my go-to packages on the CPAN. It's a fantastic tool for building and comparing sets of arbitrary values. If you find yourself trying to shoehorn hashes into your ideal data structure using keys() and map(), you might consider using this rich, functional OO interface instead.
the author is no longer maintaining Net::SFTP. the last release was in 2005. several bugs exist in this package, including documentation that conflicts with the implementation (see RT #27586). this package also uses wantarray (a transgression amongst interface sensibilities).
Net::CUPS works beautifully. the interface could be expanded to provide more cups/ipp functionality, but what's there is easy to use and well documented. i'd have given it a 5 overall, save for a few issues:
* Net::CUPS::IPP segfaults in 0.61 after sending a request (RT #53823)
* long-running tasks leak memory and i believe Net::CUPS is the culprit
* the interface could be improved to provide more seamless access to individual print jobs and their attributes