Fast-XML-Parser has a different philosophy. Minimum configuration, fastest response. But any new feature was costing the performance. So I designed Flexible-XML-Parser. Double in speed, multiple folds in customization. The only downside you may see that you need to spend an hour to understand its configuration. flexible-xml-parser allows to create anything you want from the XML. You may create XML stream, JSON, 3d model, HTML
This may look like any SAX but it is way more than that. It does all work that most of SAX miss without compromising performance. So have a look.