That article is of horrible quality. I'd suggest that you disregard most of what it has to say.

About AutoLoader, if you won't use most of the functions, then it should be faster. If you use a significant fraction of them, then your code will be slower. It makes development more complicated. Furthermore load time may or may not be what you want to focus on. For instance in a web environment you really want to use mod_perl and preload as much as feasible - so AutoLoader is definitely a loss.