To be fair to it, XSLT works pretty well for its intended purpose (it's just a huge memory hog, and the syntax will wear your fingers to the bone). My rant was one of semi-affectionate frustration, if you will...

However, if it starts looking like your problem will be tricky (or hideously long-winded) to solve in XSLT, it's probably best to cut your losses and just code something yourself with a DOM or a SAX parser.