It comes down to what you need it for. Its main strength is the easy maintainability of the transform, and writing your own parser generally obliterates that. With that said, sometimes a system is small and simple and really doesn't need a "fancy" solution. As long as your code-based builder is replaceable without having to change other code, no big deal.
As for the ugliness of XSL, yes it's ugly. Yes, it takes some getting used to. But once you get the hang of it (shouldn't take long IMO), it's actually smooth sailing. Compiled transforms run quite quickly in my experience, and you can certainly debug into them.
