Looks useful and easy to use-- I'll probably check it out in the next week or so. Like roboticus, most of what I do is quick hacks of a page or so rather than applications, but unlike him, a large fraction of it is XML in one form or another. I've been playing in the ebook world, and just about everything seems to be some kind of XML. I end up using a bunch of different modules depending on how complicated the thing I'm dealing with is.
And I actually prefer XML over YAML and JSON. I think it's generally easier to make sense of if you're looking at it in isolation
edit: And to address the OO topic-- I tend to use OO based modules. It's not something that I really think about too much, as I look more for whether they do what I want easily than OO or not.