The sad thing about #5 is that XPath is epic and trying to simulate queries using it in almost any programming language without just implementing it is tons of grunt work :(. When I a trying to parse through some complex data structure I still to this day find myself getting tired after writing a bunch of nested for loops resulting in my saying "screw this", convering the data to XML, and making short work of the problem with XPath (which only got better and better in subsequent releases of XSL/T).