??? this is not argument - spl_autoload very fast its allow only one call to load module - all developers use spl_autoload

APC its legacy and crappy as opcache. I think its smell from Zend. They stop (in old time) because their close ware Zend Studio must sell. And other get pain from that legacy. Im sorry.

check here for start: http://talks.php.net/show/w2e09

needs for speed can be satisfied