The API for the Perl module is still nasty but a bunch of bugs have been fixed which make it quite usable. I plan on uploading some other modules in the coming months which make utilise Net::LibNIDS to do their work.
If you use it, make sure you use the latest version of libnids (currently v1.24) as it fixes a bunch of important bugs. This currently isn’t in Debian/Ubuntu and the maintainer has disappeared, so compile from source for now. Red Hat based distributions get it easy it seems, as somebody has already compiled it for RHEL4 or later.