This module has saved my life and brain multiple times so far.
I use it mainly for processing 3rd party supplied, kinda awkward XML using XPath expressions. The documentation is - as mentioned in other reviews - kind of sparse, but somehow even I was able to get my work done.
Speed is no problem too, as it's a frontend class to libxml2.
Nice de-facto drop in replacement for the old Class::Methodmaker 1.x. We use it in a large scale OOP application @ $work and i am migrating a lot of smaller applications/modules to it atm.