I've been reading the excellent PHP books by Larry Ullman. Today I began working with his PHP5 Advanced book where he uses the "MySQL Improved" function throughout all his tutorials.

The only problem is he never explains exactly why he uses the improved functions versus the non-improved in his previous books. There is no explanation as what the improved functions do.

So my question is, should I be rewriting my code for my projects to use the improved functions? I also hear there are settings that need to be done in order to even use the function. Is it worth the time? Is it mature/developed enough to use?

Thanks!