[Zope] Parsed XML

I have been using the ParsedXML product. Anyone else out there with experience using this product? My immediate concern is performance. Relatively simple operations take long times. For example, I have several related chunks of ParsedXML ranging in size from 1K to 14K and averaging about 5K. (Of course that doesn't say much about the structural complexity, but it's fair to say that each xml document has 20 to 100 nodes. I have an External Method that PrettyPrints the XML and writes the result to a file. For the 60K of XML it takes 72 seconds of (mostly) dedicated processing. Any ideas why ParsedXML exhibits poor performance?