without autoload its seems useless and as monster. Its seems as broken by design.
http://stackoverflow.com/questions/4788452/does-autoload-rea...
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
more refine answer: just use spl_autoload_register