Streaming APIs for XML Parsers "The performance of the five parsers was measured over a large number of XML documents." BEA, Oracle, SJSXP, XPP3 and Woodstox compared. The last two come out on top, although "...XPP3 is based on XmlPullParser APIs and not JSR-173 compliant. XPP3 is a parsing API that will work with small devices (J2ME compatible)." SJSXP has the advantage that it supports, "...symmetrical bi-directional APIs that can both read and write XML documents using the same representation of XML."
Via StAX parsing performance paper.