I finally find somebody that is using pdflib also. We've used this module for over 2 1/2 years on a pretty large shipping company's site. Back then there was no real pdf perl module, so pdflib was what we used. It was pretty easy and very stable. In fact, so stable, that we're still using version 2.0 and they're now up to 4.x. No sense changing what isn't broken.
Forgot to mention the use of XML is great. Starting to make me rethink our site design now. :)