IT[X] unstable - why?

Hi, on http://pear.php.net/manual/en/packages.templates.itx.php there's stated that IntegratedTemplateExtension is only a wrapper class for PHPLib Template and that it shouldn't be used in new projects. But if you look at the source, you'll find that IT[X] inherits most of IT's methods and extends IT only with some methods for including blocks from a file. So why should it not be classified as stable as IT? I'm using IT[X] in my projects and hasn't had any problem so far. If there are some known problems i'd like to hear about them. Shouldn't be to hard to make it stable then. We shouldn't be too unobtrusive about some of the PEAR classes if we want PEAR to become more adopted - they are often more usable than their authors might think :). Michael