In previous decades, as I read these kinds of papers and came up to these omission sections, my reaction was to doubt that the method was in fact practical. (Benchmarking against Xerces, the slowest parser, did not help, either: how it compares to MSXML is more compelling.)
I don't think that, Xerces is the slowest XML parser. Our measurements show that, its quite a performant XML parser for various production scenarios. Also, Xerces and JDK share the same XML implementation code base.
But I'd also agree that, MSXML should be faster on windows systems, since its available as native platform code.
